Kickin' it up a notch

Discussion in 'Start Your Journey Here' started by Bruce, Jan 17, 2007.

  1. Bruce

    Bruce cheapskate

    Hey, all!

    I've been surfing the site for several months, working on my technique, and decided to join so I could take it to the next level.

    I'm basically a cyclist on sabbatical with some exposure to automotive engineering (My dad recently retired from GM, and I spent a summer in Corvette Engineering before graduating from MIT in `92), so I'm aware of a lot of the physics and mechanics of what's going on even though I haven't tinkered with engines much. Between commuting and ultramarathon riding, I've put in about 100,000 miles on the bike. I bought a car in July to alleviate some chronic health issues; I expect to be back on the bike within a year or so, but I expect to keep the car.

    My car is a `99 Chevy Prizm, a Corolla clone for less money. I bought it for its low overall cost (purchase, maintenance, gas cost), high reliability and good safety record. I figured the majority of my driving would be just back and forth to work, so a small vehicle made sense despite the allure of a wagon for ride support during cycling events (wagon selection in my price range was limited anyway; there were a lot fewer models a few years ago than there are now). I expected that some of my driving would be for solo checks of bike routes, so I bought an automatic (4-sp, locking TC) so I could drive while taking notes. Unfortunately, the auto will hurt optimizing FE with my particular commute; even though the auto has a taller final ratio than the manual, at the lower speeds I'm driving the TCC is unlocked most of the time. I didn't know I'd be interested in hypermiling when I bought the car; if I had, I probably would've given stronger consideration to a Metro with a stick.

    So far, I haven't made many modifications. I've blocked most to all of the intake depending on temperatures, unplugged the AC clutch (it was running all the time) changed to 3 quarts 5-30/1 quart 5-20, all synthetic, installed a SG II and am gradually raising the tire pressures. I'd been running 40/38 F/R based on a 35 PSI max sidewall, but I found last night that only one tire (new tires were installed by the dealer) was rated for 35 PSI max; the other three are rated for 44. They're all the same model (Radial LL650 M+S) but different makes (35 is Segura and 44s are Pro Meter). As of this morning, I'm using 44 in all and will probably bring it up to 50 in the Pro Meters tomorrow. Fortunately, the 35 PSI tire is already on the rear where it belongs. :)

    The car appears to have its best cruising FE in the 40-45 MPH range with constant throttle after locking up the TCC in fourth gear (>43-44 MPH), as you'd expect. Next best is around 30 MPH in fourth gear, TCC unlocked. Many of the speed limits are 35, in which case I'll accelerate to 44 on a downhill and gradually drift down to 40 without unlocking the TCC. The TCC unlocks if I coast, so the TPS on the Scangauge helps a lot when trying to find out how much further I can let off the gas without unlocking.

    I've already modified my former commute and found a route that is shorter, faster and has fewer stops (all a plus). My current commute is 16 miles of fairly shallow rolling hills, with speed limits ranging from 20 to 55 and an average speed around 30-35. The route to work has a stop, four yields and two lights; the route home has three lights and six yields. The five miles at the work end are expressway. On nights that I've worked late, I've occasionally been able to DWB from a stoplight a couple of blocks from work until I stop to back into my driveway. Most afternoons, there's relatively heavy stop-and-go going home, and traffic backs up at the lights. I was driving much more efficiently when I was working 12-hour days in October, but I wasn't able to do much else. :(

    FASing on hills doesn't appear to make much difference because I have an automatic (no bump starting = less efficient start) and most of the hills are short enough that I can't coast very long. FASing to red/stale green lights is a no-brainer, especially where light cycle lengths are known to be long.

    I coast in neutral where I'd come out ahead doing it, and leave it neutral at short lights. I'm pretty used to using neutral at stops, since it's a good practice for driving on ice anyway.

    It's tough to come out ahead P&Ging with the automatic, since I can't have a mostly-open throttle and low RPMs at the same time to reduce pumping losses, and a FAS glide doesn't last long enough to make the startup hit worthwhile.

    DWL seems to help but is hard to do on rolling hills at low speeds without ticking off other motorists because the speed variation is so huge. I'm guessing that the best compromise may be to maintain speed for the bottom part of the hill, then let it run out near the top. I do my best to delay acceleration until the downhill parts of a staircase descent, or the flat parts of a staircase ascent, figuring that this minimizes the fluid shear (and energy loss) in the torque converter at lower speeds.

    I've generally been trying to use more throttle on downhills than on uphills at low speeds where the TCC is unlocked, a constant 40 MPH with the TCC locked when the speed limit is 35, and constant throttle at higher speeds. I'm able to keep in the 50-55 MPH range on the expressway without getting raged by others.

    I practice face-out/PP parking and smart braking where possible, draft trucks on the expressway when there's a good opportunity, and do my best to keep my momentum on turns when the roads are dry. I've cleaned out the garage and am keeping the car inside to minimize the FE hit from warming up.

    I haven't yet figured out the optimum way to accelerate. My best guess has been a brisk acceleration to 30, let off to shift to 4th, more gradual acceleration to 45 to keep it in 4th, let off to lock the TCC, then a bit harder if more speed is needed. I should probably do some experiments at some point to find the optimum rate.

    It's only a 25 minute commute in the morning, so I probably won't be able to wring out huge mileages. OTOH, I'm not using much gas, either -- less than a gallon per day. :) I've been able to hold about 34-35 MPG tanks so far despite the decreases in temperature; EPA mixed is 31 and most users get around 30. I'd like to keep it around 35 MPG the rest of the winter, after which it should rise naturally during the summer.

    Any thoughts?
     
    Last edited: Jan 17, 2007
  2. brick

    brick Answers to "that guy."

    Welcome! That's one of the better intros we've had I think. Your choice of car was a good one IMO and it sounds like you have a really good handle on what you are doing behind the wheel. You should be pleasantly surprised come spring if you can maintain 35mpg in freezing or near-freezing weather.
     
  3. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___Great intro and thanks for posting the details for us to try and help. I looked your Prizm up and it was rated at 28/36 w/ the 4 speed Auto. Not a bad choice for a 99 in fact!

    ___You have the oil type sorted out but I assume you are using a 5-30 mix because of the manuals recommendation. Nothing wrong with that but I would be using 5W-20 all around myself? Those tires … I have no idea what kind they are or their RRC but I bet your Prizm would receive a little boost the next time they are in need of a change with a name brand LRR tire and w/ Max sidewall’s of 44 all around. That one tire w/ a 35 Max sidewall in the rear bothers me a little is all? 50 #’s will give you another little push to what appears to be a 40-mpg tank goal this early on?

    ___And to the heart of my reply.

    Many of the speed limits are 35” AND “my current commute is 16 miles of fairly shallow rolling hills, with speed limits ranging from 20 to 55 and an average speed around 30-35.

    ___Oh my god what 95% of us would do for that kind of speed limit and terrain on our daily grinds! All that is needed is for you to take advantage of those speeds and terrain given this is primo P&G territory for a non-hybrid w/ an automatic or any other vehicle known to man imho ;) Do not worry so much about TC lock up but if you truly understand the many safety and HW based limitations of a FAS (it sounds like you already know about your Prizm’s Brake and PS limitations) it is time to start taking advantage of those limits and that terrain. Since you are already SG-II equipped, when and where applicable, why not consider a load of maybe 70 - 90% on your pulse w/ a range of maybe 25 - 45 mph. The low end would be dictated by traffic of course but with traffic, maybe a 33 mph low w/ a 45 mph top end in the 35 mph limited roadways. Depending on the delta and stop lights/signs just after the top of those elevations, I would recommend trying to peak at an absolute minimum speed if the slope is steep enough to allow a terminal velocity of traffic around you on the down slope afterwards. If it is not steep enough for a slight acceleration to the limits, and there are no traffic lights/signs ahead, accelerate down the previous slope and maybe ¾ the way up into the climb with a terminal above the current limit of 5 - 10 mph. Start your FAS before the crest so that you are just a touch above the limits (as you crest) and then let the glide go for as long as traffic will allow as your speed bleeds away on the back side(s). Forget about a NICE-On’s unless able to ride Fuel Cut while in gear allowing for traffic, obstacles or conditions to slow your progress riding Engine braking down to 1,000 RPM or so and FAS from there.

    ___The above is a very generic blueprint for what I imagine you are facing - hill crest after hill crest but as always, you will come up with a better overall solution of your own once you start your own analysis of the FE achieved through a given section of roadway/commute.

    ___I do not know how fast your SG-II responds to a FAS in your Prism (recent gen Honda’s, Acura’s, and non-hybrid Toyota’s have an almost 5 second lag before the data stream begins to update) but jump on a real P&G routine w/ rhythm and your numbers will get stupid high real fast.

    ___Lastly, keep an eye on that 12V in one of your SG-II’s readouts as all us Auto drivers have to for obvious reasons ;)

    ___Good Luck and hopefully Tim and I have helped!

    ___Wayne
     
  4. Chuck

    Chuck just the messenger

    Welcome Bruce!

    That was a good intro.

    It reminded me of a story of a high school class around 1980 disassembled a Trans AM, When they put if back together - it's fuel economy doubled, telling you they would have made darn good employees....or maybe the QA needed upgrading.
     
  5. Bruce

    Bruce cheapskate

    Thanks for the compliments on the car. Yes, I've been using 5-30 mix because of the manual's recommendation.

    The oddball tire is a bit disconcerting, but there's no point in dumping new tires for several hundred dollars to save a few bucks' worth of gas...I may as well wear them out first. Given my history with my last car (a `78 Malibu I owned from `85 to `99), they'll probably fall apart from rot before I wear them out if I'm back on the bike within the next year, so it's probably just as well if they're high RR...they won't waste as much gas over their life on my car as they would on someone else's. :)

    I'm having some difficulty deciphering your paragraph about the commute.

    Are you advocating a pulse that's a large percentage of full throttle? That seems to run counter to the notion of avoiding jackrabbit starts.

    There's some amount of variation but most of the hills are minor undulations in terrain, maybe 10-30 feet of elevation -- just enough to keep the road from being a pancake in most places. The undulations are short enough that a FAS would only last a couple of seconds, so most are not worth it. I can coast down in neutral with the ICE on, but coasting down runs counter to my understanding of DWL. My understanding of DWL is to use more throttle going down a hill than going up to maintain a set MPG. If I ICE-on coast down a gentle descent, I'll necessarily need to use more throttle on the ascent to maintain speed, especially if I've lost speed while coasting. So where is it best to apply throttle? Or are you talking about alternating DWL and FAS?

    I've set the SG-II's engine type to Hybrid, and it appears to read okay (9999 MPG) during a FAS. I've been keeping an eye on the voltage, have been keeping it above 11.6 and won't FAS when it gets too low. I'll generally shut the headlights off but leave the marker lights on after I've stopped at a light to save some juice. Unfortunately, I bought a new battery last fall and didn't read about the Optima until just recently.
     
    Last edited: Jan 17, 2007
  6. Bruce

    Bruce cheapskate

    After reviewing the paragraph on the commute several times, I think I've figured it out...FAS just before a crest and hit just above nothing at the crest if I'll gain speed or just above the limit if I'll lose it or stay the same. I'm doing that now.

    There are only a half-dozen places on the commute that are really ripe for a FAS, but I may be able to work in some more if I'm really aggressive about it and I only need a seven second minimum to come out ahead. I still need to figure out about the acceleration rate. Also, if you FAS over most of a roller, you'll need to accelerate up part of the next one, and I was under the impression that accelerating up a hill is one of the worst things you can do for FE.
     
  7. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___The tires are a problem but you should only replace them when they are ready. Sorry that there was a mismatch from the dealership :(

    ___70 - 90% load is not full throttle in the least so do not think of it in those terms. You have a data display with LD (load) vs. the rest. Just swap one of your current data points for it and you will see what we are talking about. If you were without an SG-II, I would say keep your machine less than 2K during accel’s and let it climb in speed normally.

    [​IMG]
    Upper left data point in your SG-II gauge display is your “Load” readout.​

    ___10 - 30’ hills is what I drive on a daily basis. If you don’t want to FAS for any reason except FE, I would not ask you to ever use it but from your intro and commute, yes, it will bump you up by more then just a few mpg’s when used appropriately. You are going to run a FAS far longer then a few seconds and it doesn’t matter if you are in a bumper to bumper Stop and Crawl or out on the highway heading into an exit ¾ + miles ahead form 60 +. You have to judge traffic flow so that you are moving in on it before the FAS and are slowly falling back in place by the time you are ready to either pulse back up, exit the roadway, or come to a stop. Timing is critical for safety reasons of course so be very very careful but when you are ready, busting the EPA in your Prizm will be child’s play. You have to trust me as I have used the gamut of techniques in everything from 4WD SUV’s to B-Class sized coupes and using the proper tool(s) at the appropriate times allows numbers you are not going to believe! When you get a handle on all of this, you will be busting out tanks that will make a non-trained driver of any type wonder how in the heck does Bruce do that :) Your commute description just sounds absolutely too juicy to throw it away. Ask any Prius II driver here what they think about your commutes and they too will say, “Let me at it” :D

    ___DWL. If you are not HS (High Speed) or MS (Mid-speed) P&G’ing, you want to DWL over all those 10 - 30’ rises and falls. Let us say you are in a 50 mph limited section of your commute. Enter the trough at 51 and slowly bleed off speed while maintaining your iFCD at a given FE (50 mpg for example). By the time you reach the peak of the overpass or hill, you should be down to let us say 48 mph with the iFCD still holding 50 mpg. On the back side, you will more then likely see your iFCD bump way up as you are re-accelerating back to your initial target of 53 mph and by the flat, you are right back to the same speed you entered. I ma guessing on those numbers but I have to believe the 1.8 in your Prizm acts very similar to the 1.8 in a well setup Corolla w/ Auto (EPA rated 29/38) and in the summer months, 50 - 55 mpg at those speeds is almost a guarantee.

    ___Lastly, I want you to get those tires pressed up to 50, drive down a flat section of roadway at 45 and back of to 40 so your TC is locked up and watch your iFCD. Do the same for 50, and 60 mph. If you are running relatively steady state with a well setup Prizm, that 40 - 50 mph range should also shock you. I know the 03 – 07 Corolla’s will camp at 50 - 55 mpg at those speeds and I bet yours will too. Now all you need to do is try and maintain a steady state speed while DWL using anticipatory focus for timing through the lights and you have all the basics figured out.

    ___Good Luck

    ___Wayne
     
  8. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___Whoops, we crossed paths on my reply above.

    ___You don’t normally want to accel on an uphill as the FE is atrocious but if you are P&G’ing or pushing a FAS for the furthest glides, sometimes it has to be done. What you really want in a semi-hilly area is to pull 2 or 3 crests in a FAS for the price of one pulse as this is where the really crazy 90 + mpg like numbers from your Prizm can come from.

    ___Good Luck

    ___Wayne
     
  9. Bruce

    Bruce cheapskate

    Okay. I'll try to FAS a bit more on the way home, keep the engine load to 70-90% on pulses and inflate to 50 PSI in the morning.

    90+ sounds very improbable, but we'll see. Best I've seen on a commute so far is a tad over 40, and that was when it was still warm.

    I have noticed the FE at 40 with the TCC locked up, so I try to keep it there when practical.
     
  10. diamondlarry

    diamondlarry Super MPG Man/god :D

    He used to tell me that 60-70 mpg segments were possible in my Saturn when it was warm and I thought he was crazy. :D Now, I just got back from taking my daughter to youth group and pulled a 63.3 in 20F temps.
     
  11. Bruce

    Bruce cheapskate

    Obviously, Wayne can get really good mileage, but how is still a mystery to me. I'm using most of the tools and am only doing about 115% of EPA.

    I tried FASing a bit more on the way home and pulsing at 70-90 LOD. It's roughly the same acceleration I normally use, perhaps slightly more aggressive. Mileage was 32.6 MPG for the trip, down from 36.0 this morning...although this start was from 15°F outside instead of 45°F in the garage (followed by 10°F outside).

    I must be doing something wrong. In order to double my mileage with frequent FASs, I'd need to have the engine off something like 2/3 of the time. I have no idea how I can pull that off in traffic at speed, let alone keep the battery charged -- AFAIK, the battery can only charge at about 1/10 the rate it's being used, so I'd only be able to coast about 1/10 of the time steady state. I put the battery on a charger to make sure it'll start in the morning, because the voltage was pretty low by the time I got home.

    I forgot to shift to neutral on one of the glides, keyed back to IG-I and back to IG-II; the engine kept running. Any idea if my car cuts fuel completely when coasting in gear at speed? The SG-II indicates the same FE numbers at a given speed with ICE-on coasting, regardless if the shifter is in N or D.
     
    Last edited: Jan 18, 2007
  12. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___Let us start with some basics as to the how’s and why’s P&G works in the P&G plus Warp Stealth in the Prius II for maximum Fuel Economy … article and then move on to the Beating the EPA - The Why’s and how to Hypermile.

    ___I would like you to pay close attention the pulse rates/glide distances description in the first and the actual EPA City test cycle in the second. All we are doing is taking the EPA’s test cycles and smoothing them out with better technique and better setup. I also want you to pay close attention to “Speed Kills FE” section in Sect. II of the second article. Just because a hybrid is shown does not mean your car has any less of an increase in FE above the EPA combined on a percentage basis at those speeds then a Hybrid does. I recently tested a Toyota Corolla w/ Auto and at 50 mph, she was showing 50 - 55 mpg in 40 degree temps. I am almost positive your Prizm will show a similar number at those speeds because even on the EPA in a non-setup Prizm, it punched out 36 mpg on the highway test cycle.

    ___Please do not get discouraged as we will help you every step of the way. Just take small steps and it will get better very soon.

    ___About your 12V. You are assuming you are riding it down during a FAS and you are not. Just watch the voltage on the SG-II. I am assuming you are practicing the techniques in the daylight without lights? I hope so anyway ;) With your headlights on, you will never be able to FAS “At Will” due to the OEM 12V not having the CAP to take any kind of distant ICE-Off glides. You are only using current to keep the electronics booted up during the day and in a 99 Prizm, there will be a minimal draw. You are using the 12V basically for starting and you have quite a bit of CAP without any charging whatsoever. Think of going out to your car, pulling the plug wires and start turning it over on the starter. How long would it turn over? Maybe 1.5 minutes before it grinds to a halt? You are using maybe 3 - 4 seconds worth of that after every FAS and you are charging on every pulse. Except with a smallish cap OEM battery, you can even FAS at night without issue but there are always limits. Just watch the 12V signal in your SG-II and it will tell you that below 11.7 V (as a guesstimate) you had better begin a pulse to bring the 12V back up or you will be below the current capability needed to spin her over to re-ignite the ICE.

    ___About Fuel Cut. I cannot say for sure that your 99 goes into Fuel Cut but I bet it does. You will feel engine braking in Gear while slowing and this is when fuel cut happens. The problem with fuel cut under engine braking is that you are throwing away that glide distance (momentum) to compressing air and throwing it back out the tailpipe. A NICE-ON vs. ICE-Off FAS is worth about 20% less from 50 down to about 10 mph in the Accord. It is the difference between a 40 mpg segment including a pulse to a 50 mpg one w/ a 75’ climb included which is a huge number in my book.

    ___Good Luck

    ___Wayne
     
  13. Bruce

    Bruce cheapskate

    I've seen the first article but wasn't sure what I'm supposed to get out of it, since it's Prius-specific. There's no way I can do a 50 MPG pulse, since the best the car will do when cruising at 40 with the TCC locked up was 46 MPG or so this morning. While I'm accelerating at a slow rate, the SG-II usually shows about 15-20 MPG.

    The second article got me interested in the site a few months ago, and I review it weekly to see if there's anything else I can put into my routine.

    If I'm lucky and get out of work on time in the afternoon (I had to stay late last night) I can usually get home by the time it's getting dark. Otherwise, all my driving is at night, so I'm draining the battery during a glide. The car also has automatic headlights and DRLs, which complicates battery management somewhat.

    Most of my ride is in heavy traffic on a 2-lane road with only two passing zones. My conclusion about speeds relative to the limit is this:

    10 MPH over: you'll get a ticket.
    5 MPH over: no problem.
    at the limit: no problem.
    5 MPH under: the guy behind you will flash his lights, start honking and then pass over a double yellow line if you don't respond.

    The situation is so crazy but well known that one local town uses advisory speed limits that are strictly enforced but 5 MPH _over_ the former posted limit, with the understanding that all the traffic should move at exactly the advisory limit -- no more, no less. As a cyclist, I was rather amused by it, because not even Lance could've gone at the limit up the hills on the road. (This is one example, but it is not the situation on the roads I use for my driving commute.)

    I P&Gd a bit less this morning -- maybe 2-3 times over the ride, and my mileage was 34.7 MPG at a 10°F ambient, coming from a 40°F garage. Historically, my experience has been that the more I P&G, the worse the mileage. I wasn't able to get much out of a glide this morning because the car wouldn't glide very far in the low temps.

    Perhaps I need to give a much more detailed description of my commute route, but I'd need to do it on the weekend so I'd have more time to find all the distances.

    The example in the last four paragraphs of page 3 of this article http://nbtsc.org/~ryland/RoadAndTrackArticle/ demonstrated that P&G didn't yield a significant advantage over just cruising unless bump starting is used. How does what you are doing differ from this example? How does a Corolla/Prizm with pull a 90 MPG segment when these guys are only getting a little more at very low speeds with cars that have a 60% better EPA FE?
     
    Last edited: Jan 18, 2007
  14. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___The Prius article is for explaining why P&G works. You cannot Pulse at 50 mpg’s but you can pulse at 16 and that is the point I want you to consider and understand. You do not need the TC to be locked up for great FE. P&G works no matter if it’s a hybrid or non although the benefit decreases quickly with increasing speeds and tighter ranges. You do need to allow an appropriate Glide distance however or it is not worth performing. When coming into any light or sign, you should consider a FAS other then the Fuel Cut situation but if you are relying on Fuel cut w/ ICE-breaking, you are coming in far to hot in the first place.

    ___Yes, DRL’s can be problematic. Fortunately, longer days are already heading our way by a minute or two daily and after DST, you should have day light hours both too and from depending on your work schedule. Use the 12V display and it will tell you when its time to light her up and maybe perform some NICE-On’s but a NICE-On will not help you move up to what you will soon be capable of.

    ___5 mph under … You should be building a buffer behind when you pulse but best of all is that both lanes will not be filled bumper to bumper at most times of the day or night. Anyone behind will not be pulsing with you so if you are P&G’ing between 30 and 40 in a 35 zone, no problems. You will become much more aware of what is ahead and behind when you start pushing as you simply have too …

    ___Just keep working it and don’t give up … You will find whatever balance you need while also receiving exceptional FE. We can also perform a case study on your route once you post that detail later this week if you think you need some more help.

    ___Good Luck

    ___Wayne
     
  15. brick

    brick Answers to "that guy."


    This is the same thing I'm up against most days, except that around here I'll get tailgated, honked at, flashed, and passed for driving at the limit. Even yesterday I had a guy behind me making hand gestures and tailgating while I was 5-under but within 300ft of the next stop sign. That morning I was passed illegally because, apparently, I wasn't accelerating fast enough from a stop sign in a residential neighborhood. I have decided to live with it and no longer even acknowledge that the idiots exist. The only notable exception was when I rolled up behind a repeat offender at a light (read: passed me every day in his rice rocket doing 10-15 over the limit) and made a big production out of pulling out pen & paper to write down his plate numbers while he watched in his rear view. He had to recognize me from our daily encounter and was paying attention. Anyway I used to see him every day and since then I haven't seen him even once. In short, we have to be courteous to other traffic for their sake and ours but there are limits (usually written on signs in big numbers) to what they can expect.

    As for P&G, my experience is that it's a touchy art. I have had the same experience of going overboard and realizing at the end of a segment that my mileage is in the toilet. What seems to work in my case (and particularly this morning) is to let go of P&G when terrain is sub-optimal and take the good opportunities when they arise. It sounds like you have learned that for yourself, but don't think it's just you having trouble.

    I don't really understand how the folks like Wayne, Larry, and Chris can be so consistent with numbers that far above the EPA, either. Those guys are blessed with the right touch, the right attitude, and at least sometimes the right driving environment to make magic happen. However don't feel that you have to compete against them or feel bad if your numbers aren't as good because, in the end, every situation is different and there's only one person you can really compete against: yourself. Just don't even worry about it as long as you are doing the best you can within watever limits are comfortable for you.
     
  16. brick

    brick Answers to "that guy."

    Not to hijack the thread but I have tried that and it just doesn't seem to work. If the zone is 35mph and I'm P&Ging between 30 and 40, traffic DOES inevitably catch up. Once that happens they DO pulse with me and automatically ride my bumper all the way down to 35 at which point I give up. Is there some other variable that puts it all together?
     
  17. Bruce

    Bruce cheapskate

    I think brick has a better handle on what I'm up against, since he's from the Northeast as well. The roads out here are improved cowpaths with lots of hills and turns and short sight distances. Passing zones are rare to nonexistent. Many hills are substantial enough that at residential speed limits, you only have enough momentum from a glide to make it down one hill and partway up the next before the car stops completely, and the hills vary widely in profile and elevation. It's very different from most of the rest of the country, where the roads are on the grid system and have passing zones with long sight distances. If you pull up a Google map of the Boston area and compare it to, say, Oklahoma or Michigan, you'll see what I mean. My wife and I administer cycling events on these roads and it's often challenging to pass riders safely.

    On the medium-speed roads, there's enough traffic that >10MPH variation generally isn't tolerated well unless there's a decreasing speed limit during the glide (I only have two of these going to work, for example). It sounds like a glide needs to cover a substantially greater speed range than 10 MPH if it is to help rather than hurt FE for the trip.

    - Bruce
     
  18. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Bruce:

    ___Tim made a very good point. Tarabell’s article on External Factors Affecting Mileage, or why “YMMV” would be an appropriate one to read at this point. Don’t worry about the busting the EPA in the teeth just yet but it is waiting for you. Just begin with the basics and it will come to you like a bolt of lightning out of the blue very soon :D

    ___Tim, in some instances, I will pull into the left lane, let a tailgater pass, and move right back into the right when driving around locally on four lane roads with 30 - 45 mph limits. I have actually had to do this on the Interstates when driving the limit because some SOB wants to drive 10 + over in the far right lane but will not pull around when traffic is completely clear in the center and lanes further to the left. Just the way some people view the roadway I guess? The OTR (Over the Road) drivers always catch a RR from way back and pull around usually ¼ mile or more behind but the cel phone talking, paper reading, make up applying types just don’t get it sometimes :( As I am sure you are, I am driving from my rear view as much as my windscreen so as to time the lane to lane dances if needed just right. Hopefully you can make it out to HF2007 and we can do some Chicago style hypermiling in the Accord in heavy traffic so you can see how I am swinging that beast around. I would love to see you swinging your Prius around as I know you will be when the warmer temps arrive and a Glide is a Glide each time you throw her into one :)

    ___If I am within a band of 30 - 40 on a two lane - 35 mph limited roadway and 2 lanes of traffic are starting to crowd, I can pick it up to 35 - 45 as I am already 10 over on the pulse. This is one of those rare instances when I can out hybrid a hybrid but I really do not see this that much given I am usually out the door by 04:00 AM (little to no traffic) and coming home in the heat of Rush (things are bumper to bumper and moving decently but not crazily) or battling the stop and crawls in the early afternoons out on the Interstate. I like driving the Ranger in the city/towns because I can swing it from a Pulse to Glides so much faster then with the Accord with its Auto. What I will never do is accelerate into a red light even with traffic behind. I arrive to the bumper in front of me just as fast as everyone else would and they will have to follow at a coast down speed since I am not impeding anyone’s progress through the light. I have had some flashing lights and honks with this (daahhh ;)) and then arrive at the bumper in front of me just as they are moving away and I see the guy/gal behind with a big bright light bulb lit up on top of their head as I wave and they sometimes even wave back. “Oh, that is what he was doing”. Remember that I am a very passive/aggressive driver and if I see a P&G opportunity with a lane change and to come back into the right while passing in a FAS, I will take it. Most wouldn’t think that far ahead nor would they want to in most instances as it is a lot of calculating?

    ___Good Luck

    ___Wayne
     
  19. Bruce

    Bruce cheapskate

    Drivers in the NE have some of the shortest fuses in the country. Locals have called it the "New York effect". Several years ago, I was waiting for traffic to clear to make a left turn out of a McDonald's onto a busy roadway; in less than a minute, two cars from behind went around my left side to turn right rather than wait.

    There are lots of dashboard videos on Youtube of people doing illegal top-speed runs, commutes of 16 miles in 3 minutes, etc.

    Somebody needs to post a dashboard video with a scangauge showing a fuel-efficient commute.
     
    Last edited: Jan 18, 2007
  20. brick

    brick Answers to "that guy."

    I agree. It would be fun to share videos of our daily grinds w/ a little commentary and FE feedback goodness. There are obvious privacy concerns ("This is me leaving my house" etc.) but that could be dealt with in post-production if it's an issue. I bet there's a lot to be learned from that, as it's not every day you get to ride along with someone else who drives with fuel efficiency in mind, let alone for maximum efficiency. There is a limit to how much understanding can be gained from the written word vs. a real demonstration.
     

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