Archives

Hello all,

I just joined this site, I've been a fan of this forum for quite some time and I figured it's finally time to try to do some posting of my own. As you can tell by the title I'm trying to achieve 40 mpg (city) out of my SL1. I'm currently around 34 mpg average in the winter and sometimes I can get 37 mpg in the summer out of it. I've done a couple things so far but if anyone has any other ideas it would be quite welcome.

So far I've done,
-Minor weight reduction (seats, spare tire and jack)
-LRR tires (Goodyear Assurance fuel max)
-Warm air intake
-pseudo hypermiling techniques (drift to stops, easy on gas pedal, obey speed limit signs)
-synthetic tranny and motor oil (Currently Mobil 1 but getting ready to switch to AMS oil, only because the hippie in me tells me Exxon Mobil is evil)
-I have a ScanGuage II as well

Future ideas
-Pulling AC compressor and Power steering pump
-Lightweight rims
-Lightweight flywheel

I'm not looking into a engine rebuild or anything drastic, the plan I have is to be able to put the car back together if there ever comes a time when I want to sell it. Also I keep it tuned up to the best of my abilities (new plugs, wires, and fluids every summer)

If anyone has some other ideas that would be most beneficial!

P.S. I have not tried pulse and glide either I guess I should try it but I don't see how slowing then accelerating gets better gas mileage than maintaining a constant speed, at least in an internal combustion engine. What % increase does it net in a little four banger?

When you say "drift to stops," you mean coast to stops?

I had an SL1 with an automatic, and albeit a slightly different technique, it netted a few more MPG, and should give you bigger gains with the 5 speed.

Pulse and glide can give you significantly better numbers than DWL in the city if done and timed right and even moreso if you decide to NICE-OFF coast. I had an SL1 with an automatic, and albeit a slightly different technique, it netted a few more MPG, and should give you bigger gains with the 5 speed.

I would focus on practicing P&G on a deserted road somewhere if you can. The idea is to coast longer than you accelerate and have your trip MPG higher after the end of each coast. You'll want to accelerate at about 50-70% LOD to the speed limit (or less if you can) and then coast in neutral down to a speed of your choosing... just don't make it too slow for traffic conditions... sometimes a 5 mph delta is all you need, but better gains can come from bigger deltas. Timing the lights and DWB will also help you by not having to accelerate from a stop. Make sure to push the turbo button (ie turn off the A/C compressor, until you pull it at least) and pump up the tires to max sidewall.

I do as a matter of fact mean coast to stops. Thanks for the correction.

I'm still iffy on the max sidewall pressure. I'm currently at 40-45 (It's been a while since I checked them. Will the extra 5-10 psi help? My max sidewall is 50 psi.

I'll give P&G a try. I also never drive with the ac on or the heater.

I guess this is an added question. My wife and I leased a Prius but she refuses to do any hypermiling techniques. She gets on average 42 mpg in the thing. Is there anything I can do besides pump up her tires to get her better gas mileage while she refuses to modify any of her driving techniques?

Thanks

Welcome, Justin.

80%-90% of your fuel economy gains will come from changing driving habits, so if your wife isn't willing to change, her Prius will continue to get its sub-par FE.

OTOH, you can definitely surpass her Prius' FE with your SL1 if it's a manual. If it's an automatic, 42 mpg will be a challenge. I think the AT SL1s are flat-towable. If so, you can EOC and really see some benefits from P&G.

I do as a matter of fact mean coast to stops. Thanks for the correction.

I'm still iffy on the max sidewall pressure. I'm currently at 40-45 (It's been a while since I checked them. Will the extra 5-10 psi help? My max sidewall is 50 psi.


It does. You can gradually inflate your tires until you reach a happy medium between NVH and mpg.


I guess this is an added question. My wife and I leased a Prius but she refuses to do any hypermiling techniques. She gets on average 42 mpg in the thing. Is there anything I can do besides pump up her tires to get her better gas mileage while she refuses to modify any of her driving techniques?

Thanks

Grille block to help cold starts. Can be done with pipe foam.

Ken@Japan on PriusChat gave a strategy considered safe for a Gen 3 Prius. It varies by ambient temperature:
http://priuschat.com/forums/gen-iii-2010-prius-accessories-modifications/62556-2010-prius-grill-blocking-strategy.html#post862373

Gen 2 would be a bit different, basically inverted because of where components are.

I understand on the wife's techniques. If your wife is like mine she just wants to get to her destination safely and without inconveniencing other drivers. I felt timing lights (and yields) and gliding to stops were the freebies that my wife would be willing to do*.

My wife dropped to 65mph on the Interstate by herself just because the Prius gets upset and whines ;) and (after my nagging) started trying to time lights but that's as far as she'll go.

So back off on pushing hypermiling generally but keep up some pressure on the freebies. Frame timing lights as a time saver, gliding to stops as relaxing.

Thanks,

Colin Wright

* And everyone should do. sudo umount /mnt/soapbox

sudo umount /mnt/soapbox

Ah.. Mac OS X or some other Unix-like variant? :D

The advice above is good -- I'll only add that you should be patient with new techniques. It takes a while to really become proficient in a number of them, and longer still to discover how best to exploit your circumstances to wring every last inch out of your fuel.

Ah.. Mac OS X or some other Unix-like variant? :D

The advice above is good -- I'll only add that you should be patient with new techniques. It takes a while to really become proficient in a number of them, and longer still to discover how best to exploit your circumstances to wring every last inch out of your fuel.

Linux (currently KDE-fied Ubuntu. Red Hat->SuSE->SUSE->OpenSUSE and then I got a new laptop). Definitely not a Mac person. I have a hard enough time using GNOME. ;)

Ah... a kindred spirit! I use GNOME, but only grudgingly. My weapon of choice is FreeBSD, though -- without sudo. ;)

My wife feels I'm going insane by trying to get better gas mileage so anytime I give suggestions on how to get better mpg she will then get frustrated and tromp on the gas (not everytime I give a suggestion but it does happen). So I figured the best way for her to not get better mpg is for me to not nag her. At least she's doing better than when she had her Malibu.

I'm getting ready to fill up for the first time to see how the warm air intake helped my mpg. After that I'll start giving P&G a try. Thanks for the advice guys.

I just had to chime in and say hi, having recently switched again to Ubuntu (last used it back in '06 or so) and entering in terminal command after command to get things setup nicely on my laptop. : D

Regarding the thread topic, I understand the challenge of convincing your spouse. Both with her and with yourself, be patient and move slowly. : D

Specifically with regard to 40 on the SL1, experiment with both P&G and DWL to see what works better for you. Personally I use a combination of both on my auto Tercel. I DWL on levels and uphills and glide toward stops, lights, or downhills. It nets me better mpg than I got when I simply did P&G while being less obtrusive to traffic. This would potentially be different in a manual, but in my auto, glides just drop gears, so it's not productive to simply P&G around town.

If it's in gear, it's not a glide. That's engine braking. You need to shift to neutral.

I always glide in neutral, but there are few automatics that will let you glide from 30 to 20 mph and maintain the same gear you were in at 30 once you pop back in gear at 20 and hit the gas.

So far I've only gone sixty miles but my AFE readout on my scanguage is giving me 40.3 mpg with only trying Pulse and Glide. I'll try delving into DWL after a tank of gas with just P&G.

Does anyone else have the problem of the Scanguage being off 2-3 mpg compared to when they fill up and do the math themselves? I keep trying to adjust the percentage but nothing seems to work.

All in all thanks for recommending P&G even if my scanguage is off by 3 mpg I'm still getting 37mpg! So far I'm at a 5 mpg increase

So far I've only gone sixty miles but my AFE readout on my scanguage is giving me 40.3 mpg with only trying Pulse and Glide. I'll try delving into DWL after a tank of gas with just P&G.

Does anyone else have the problem of the Scanguage being off 2-3 mpg compared to when they fill up and do the math themselves? I keep trying to adjust the percentage but nothing seems to work.

All in all thanks for recommending P&G even if my scanguage is off by 3 mpg I'm still getting 37mpg! So far I'm at a 5 mpg increase

Typically each car has an offset and you need to find it by adjusting the offset at each fill until you hit a sweet spot. (Menu, more, more, fillup or something like that.) There's also another setting you may need to adjust to help it calculate better. Some cars are more variable than others. In my Prius I was using a 7% offset in summer but as the temperatures dropped it increased to 8.1%.

When you get ready to fill up, do the tank limes indicated on the SG closely match up with your odometer indicated miles driven? If not, you'll have to calibrate the speed setting on the SG...this is best done with driving with a GPS to make the speeds accurate. Then you'll find out if your speedometer off and by how much.

Welcome from a fellow Hoosier, where in Indiana are you from. I am from just NE of Indy myself. I understand your frustration with the wife. I had the same issues with my wife. Although over time she accepted what I was doing realizing that it wasn't as dangerous at it seems. She even let me press up the tires in her Esteem, well until it died a few months ago. She will even do some mild hypermiling from time to time (eg. gliding, light timing, etc). As far as getting the SG to be accurate I've found the best way is to adjust the offset by half the difference. For example, if you put in 10.6 gallons and the SG says you only used 10 gallons, adjust it to 10.3. That will keep you from overshooting then having to adjust back the other direction on your next fill.

As far as getting the SG to be accurate I've found the best way is to adjust the offset by half the difference. For example, if you put in 10.6 gallons and the SG says you only used 10 gallons, adjust it to 10.3. That will keep you from overshooting then having to adjust back the other direction on your next fill.

This has been my experience as well. Otherwise, it's an ever-growing continuum of adjustments that get larger, rather than smaller. I've also noticed that a calibration that works well for mostly low-speed around town tanks is off when I take a trip at a higher average speed out of town (highway driving), and the smaller adjustments help keep everything close.

Thanks for the tips on the SG. I'll look into making the smaller adjustments. I usually change it by a half percent one way or the other so that way I don't jump over that sweet spot. But I'll give the "put it halfway between the two readings" technique a try.

Also Damionk I'm from Fort Wayne. So just a touch more NE of Indy than you! I've let up on my wife about the fuel economy issue for now. Hopefully one day she'll come around.

Ah... a kindred spirit! I use GNOME, but only grudgingly. My weapon of choice is FreeBSD, though -- without sudo. ;)

SLACKPOWER!

I just want to thank everybody for the tips. After my first fillup using pulse and glide I got 40.46 mpg. I'm definately a believer on this technique!

Excellent progress, Justin!! I know P&G surely has saved me a lot of fuel over the years. ;)

Any newer results, Justin?

Sorry I haven't replied lately.
I'm still in the 38-40 mpg range. I'm hoping with the nicer weather coming up soon I can breach the 45 mpg mark, maybe even the 50. I'm still trying to get the hang of coasting down 10 mph below the speed limit while not annoying the people behind me.

I'm also trying RLI's 0W-30 mostly for the fact that it's 40% soy, I'm not expecting to see any major changes in mileage from it though.

Welcome, Justin.

80%-90% of your fuel economy gains will come from changing driving habits, so if your wife isn't willing to change, her Prius will continue to get its sub-par FE.

OTOH, you can definitely surpass her Prius' FE with your SL1 if it's a manual. If it's an automatic, 42 mpg will be a challenge. I think the AT SL1s are flat-towable. If so, you can EOC and really see some benefits from P&G.

Yes, Saturn SL1/SL2 AT's are indeed flat-towable. I once achieved 63+ in the summer over 13 miles in my wife's '99 SL2 with EOC. I'm looking forward to that going up as I now have some well broken-in Bridgestone Ecopia's on it that I took off my Prius.

What did you put on the Prius?

Mike, I put another set of Ecopia's back on the Prius. I think I pretty well got them broken in this past weekend too. We went to Cincinnati to visit with my daughter's boyfriend's parents. On Saturday alone, we put on 138 miles. Anywhere you go seems to require getting on the freeway down there.:( Oh well, I was still able to get 50's and 60's at highway speeds even since on I-275 there were many chances to practice my warp-stealth techniques. There were times that I was reading 150+ mpg (per SGII) for several miles at a time until I had to pay the piper and go back up the other side.:p

Diamondlarry

I have a 5 speed. I'm just trying to not annoy the other people on the road by dropping 10 mph below the speed limit before going back up. I've noticed my mileage steadily dropping since some of my commutes are during "rush hour" (Fort Wayne really doesn't have one) but it's still busier than I'm used to.

I'm trying to shut the car off at stop lights to see if that can bring be back up to 40+ mpg. I'm new to it on this tank so I'll post my results in another 150 miles.

That's another thing that I have done with the Saturn is throw a pair of Goodyear Assurance Fuel Max's on it. I didn't notice much of a change though, even though they are at 50 psi as well.

When is the last time it had a tune up? Plugs and wires, air filter, stuff like that. I ask because I have heard of stock SL1s getting 40mpg highway driven normally.

my friend has a 99 SL1 WITH THE 1.9LITER he drives 70mph and gets 37--39mpg and his car has a manual tranny and 200,000 miles

The highway is no problem for me. I can get 50 mpg on the highway no problem. I'm doing this all in town. That's where I'm trying to reach the 40 mpg range, constantly.

Also I keep it regularly tuned up. I do plugs, wires, filters, and fluids every year. (Yeah I know that's crazy).

Seen an increase using hho?

What is hho?

It's one of those junk alternatives.

HHO is just another notation for H2O (water) and it is usually applied in reference to those "Brown's gas" or hydrogen generators. The basic concept is a proposed increase in combustion efficiency if you inject hydrogen into the atomized gas stream entering the cylinders. It sounds impressive but deeper delving into the theory indicates that it won't have any effect and in fact, since most systems put significant electric load on the vehicle to split water into hydrogen and oxygen they actually lower fuel economy.

We don't promote additives and bolt on components advertised to increase FE -- most of them do not work, and many actually decrease FE. The ones that do work are typically only a few percent worth of improvement... in comparison to an easy 15% with very basic hypermiling and much more if you really apply yourself.