Anyone try an FAS on the CRZ?

[TubaGuy87]

The recent purchase of my CRZ ex eventually led me to this site, which has sparked my newfound passion for hypermiling. The more I search the archives, the more articles I find for installing an FAS switch/button on other cars, but I found none for the Z. I assume this is because the CRZ is still fairly new. I was wondering if any of the tech savvy members have any experience/ advice for adding an FAS of MIMA to the Z.


(Must be late, my formatting seems sense to not make...)

[Right Lane Cruiser]

Welcome to CleanMPG!! Do you have the manual transmission? If so, a simple key FAS will work nicely with a bump start to bring the engine back online.

As of right now MIMA only exists for the first generation Insight. One of the big reasons for this is that this car has the very first iteration of Honda's IMA system with most components separated and all intra-module communication done with serial communications that can be snooped and deciphered. Newer IMA systems combined modules (such as the motor and battery control modules) as well as moved communications to the CAN bus... making it much more difficult to determine how everything works together as well as modifying communication streams for direct control. Efforts are underway but progress is quite slow.

A FAS button is definitely more convenient (especially as implemented in the first gen Insight where it is basically on demand autostop at any speed), but as long as you are monitoring the 12V status and fully aware of the situation around you using the key and bump starting work just fine. That's how I (and many others on this site) manage to pull over 200% of EPA from our manual transmission, non-hybrid vehicles.

Tell us a little about your typical driving conditions and what kind of mileage you are currently seeing from your CRZ! We love to help and that info would give us a leg up on what we should recommend. Meanwhile, I recommend perusing the page (and associated content) found at the link in my signature block (the one at the very bottom).

[TubaGuy87]

Thanks for the in-depth response!

I do drive the manual and I do FAS with the key. I just hate doing the key method as that messes with some of the feedback displays (making it seem like I'm achieving much better mpg then I really am.)

Most of my driving is highway and rural roads, very little of it flat. Between playing with the normal and eco modes, and implementing techniques like P&G, DWL, FAS, DWB, and driving like a old lady, I'm ab;e to squeeze 49 mpg out of my Z. She's still under 4000 miles, so I expect to be able to pull off 50+ mpg when the ICE is fully broken in.

[Harold]

When you coast with the CRZ the ICE is off , so really what is the advantage? If while coasting and you see regen then throttle up slightly until the regen is no longer doing regen, at that point you should coast almost as well. Maybe even better as you are not screwing around with all that other stuff? H

[Right Lane Cruiser]

Hi, Harold — the manual transmission in the CRZ doesn't have the soft glide capability that is available in CVT Honda hybrids.

TubaGuy… do you play the tuba? I love listening to the "tubist" in the Canadian Brass.

Let's take this one technique at a time. I want to be sure you've got FAS working correctly, first. What's going on with the feedback displays that inflates your mpg? My Insight occasionally sticks at zero fuel usage after a key FAS followed by a bump start but that can be corrected by flipping the key to ACC position and back quickly enough that the engine doesn't have a chance to die (basically as fast as I can manage). That seems to initiate a reset and consumption figures track correctly from there forward. Are you seeing a stuck consumption rate like this? If so, try the above process above.

You are coasting engine off with the key in the ON position, right? Are you waiting for the RPM to drop in neutral before initiating the FAS?

How long is your typical trip?

[Harold]

Hi, Sean- Are you telling me that a M/T model CRZ . The ICE does not turn off when coasting. Does the ICE stop at a street light? H

[TubaGuy87]

Sean, the CR-Z has a display menu that shows your current trip mpg and the last 3 "trip" mpg. Honda considers a trip when you turn the ignition on to when you turn it off. Thus when you FAS with the ignition it fools the display into thinking you've accomplished 60+ mpg for your last 3 trips. This isn't the end of the world, I'd just like for that screen to be a little more accurate after an FAS, other wise it's just inflating my hypermiler ego.

As for the key FAS, I'll turn the key to the accessory position, wait for the tach to drop to zero, then return the ket to IGII (on). Are you saying that I can put in in neutral, wait for the tach to settle at 1000rpm, then quickly flip the key off and on?

My typical trips are 20 to 30 miles, mostly highway.

In the M/T CRZ, the ICE will only auto stop with pressure on the brake, in neutral, and below 18mph. If you're still moving and remove your foot from the brake, the ICE will start back up. This is why I'd like to install some sort of FAS button or switch.

oh, and for the record, I do play tuba. In fact I took one with when test driving the CR-Z to make sure it fit in the back. (it does)

[Right Lane Cruiser]

Hi, Harold -- if you leave the car in gear, no soft glide. The car will autostop at a light... and some other situations.

TubaGuy, yes -- put the car in neutral first, let the tachometer get down around 1K RPM, then initiate the FAS so that the key can spend as little time as possible out of ON position. This might change the behavior of your 3 trip history but mainly you want to be sure every electronic device is online as much as possible -- notably things such as your airbags, traction control, and ABS. None of those is active when the key isn't in the ON position. It takes a little practice to find the minimum time you can have the key in ACC but it is worth the learning curve.

What speed are you traveling on the highway? 20-30mi is plenty to develop a very nice trip average. Are there any surface street alternatives? High speed P&G can be treacherous unless you have a close eye on the trip MPG -- without careful timing it can actually hurt more than it helps. Used properly though it can do a world of good. My Elantra was rated at 33mpg on the highway before the change in 2007... I can typically manage low 50s out on the highway with P&G.

Autostop is a bit more flexible than you might realize. From what Wayne was able to tell me when he drove a CRZ MT for a review (have you read the thread? It is a good read and I do recommend it) autostop works the same as in my Insight. Here are the parameters:

• Engine and cat fully warmed
• Ambient temperature high enough (not sure the actual temp requirement but it is tied to the next item)
• HVAC system in ECO mode or off
• Brake pedal depressed with transmission in neutral OR clutch pedal depressed AND selected gear either neutral or not 1st gear
• Speed at initiation 21mph or lower

With the above in mind, here is what I recommend. Drop into DFCO (Deceleration Fuel Cut-Off) with regen above 21mph. When your speed gets down to 21mph, switch to neutral while pressing the clutch and keep pressing the clutch. The car should drop into the autostop state immediately and will stay there as long as your clutch is depressed -- even if you coast to higher speeds than 21mph. This is essentially like the soft glide state of the CVT but it has less drag and doesn't offer a limited EV mode. The engine will restart if you lift off the clutch pedal, run out of braking vacuum, shift into gear, the SoC (State of Charge) gets too low, or the coolant/cat temp drops too far.

If you wanted to you could probably implement a clutch mod like I have in my Insight. It is simply a switch wired in parallel to the one on the clutch pedal -- it will fool the computers into thinking the clutch is depressed when it isn't if you complete the circuit. This is nice because I can enter autostop and stay there without keeping my foot on the clutch pedal and in my car it will disallow both assist and regen. In yours it will only disable regen (if it follows the pattern of newer models of the MT Insight and Civic Hybrid) but that can still be useful at times. It is a very easy modification to do and I implemented it in my car without even cutting or soldering any wires in the harness (I pinched new wires in the plug on the back of the stock switch on the pedal).

I have to say I'm very interested in seeing what you can end up getting out of that car! I'd love to take one for a drive sometime to see what I could pull out of it. Do you mind me asking what state you are in?

[brick]

Sounds like a ScanGauge would "fix" the display issue. That would provide instantaneous, trip, and tank FE readouts that aren't impacted by FAS. Plus you can calibrate it to miles vs. gallons calculations at fillup to improve accuracy. It's a good tool.

A MT CR-Z sounds like a "conventional" around-town hypermiler's dream. CVT hybrids are fantastic but I occasionally miss the ability to shut down the ICE at any speed, any time without regard for the whims of drive train management computers.

[TubaGuy87]

Sean,
I'll have to try out some of those techniques. I usually travel 50-65mph on the highway, I try to initiate a NICE-ON P&G as much as possible and FAS on longer down hill segments (not many). recently I've stumbled upon a sweet spot between 60 and 65 mph where i can keep the IFCD around 65mpg, I figured this out following the HCH-II SAHM by MSantos. I know the HCH-II and CR-Z are different beasts, but I thought it couldn't hurt to try. As for alternative routes, yes there are some but they're a little hilly. I was under the impression that hills were a big FE no no. Also, I've read Wayne's review of the CR-Z multiple time and all I can say is I'm not worthy!

Tim,
I have a scanguage, I use it primarily for instantaneous info. I just like the stock gauges, but if Sean's tips work, then that will no longer be a problem.


btw-I'm in the Philadelphia (PA) area.