Here is what I found that seems to provide my auto-tranny the best MPG, and especially for city driving.
The strategy I use is to work with the ECU computer and VVTi mechanism by getting to the "cruise speed" quickly. In other words, if the ECU thinks your still getting up to speed, the VVTi will not be set to economy/lean burn mode. So if for example the speed limit is 40 mph, I jump up to 42, then back off to 40...per the scan gauge, the MPG goes up to 33-35, then settles to 50 at 40 MPH. Once I settle to 40 MPH, the ECU issues a command to the VVTi to change the timing to result in lean-burn mode. The problem with some styles of driving is that people are not mindful about get to cruise fast...often starting out too slow and too gradual up to cruise speed means wasting gasoline that otherwise does not have to be wasted. Of course jumping too fast to cruise can over consume gas too. |
The Yaris has lean burn?
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Yes, but not just the Yaris...most late model small cars that have variable valve timing have it...it works with DFCO, and fancy scripts that are programmed into the ECU.
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can't believe no one has complimented you on your FE especially for such a big, heavy car.
sadly, you may very well be near your peak w/ this vehicle. but, hey, nicely done. with some help here, you may squeeze out a bit more. |
morninggasser,
I notice in your garage that you are thinking of a WAI but haven't seen proof of it working. please see my gas log and the gas log of project84 (not sure of his vehicle name) it seems to work well with the little GM cars (cavs and saturns) there have been reports of it doing nothing. it all tepends on your computer and the sensors it uses (or so I have heard). maybe also consider a grill block as well. your mileage has actually encouraged me. I was thinking of a yaris for a while but I am on the list for the smart. If I could get that mileage out of a yaris, I would probably rather do that. the waiting list for the smart is about a year and a half. I have about 8 mos to go. I may change my mind *edit* I read it again and it said CAI not WAI. well anyway warm air intakes will help in FE. |
With my auto trans the only thing I really do is shift into Neutral at longer red lights because I've watched the SGII and can see that in gear my car uses 0.45 GPH and in neutral it drops to 0.33 or around there.... other than that, I drive it extremely normally.
Only tip I can give is find out exactly where you enter your highest gear (4th gear) and drive the car at a speed that allows to be in 4th gear but not under much load. I enter 4th gear at 35mph when warmed, so I basically drive 35mph whenever possible, if the speed limit is 45, I'll slowly speed up to 45 then coast (in gear) to 35. I heard a while back that in a higher gear you can use MORE throttle and get better FE than if you allow the car to downshift.... so even at 35mph I will sometimes use 30% throttle and still be over 25mpg climbing hills whereas if the car downshifts and I'm running 3,000 RPM in 3rd gear at 35mph the MPG drops to the teens. Hope any of that helps! I tried P&G w/ neutral and found it to be a lot of effort, and after one tank of dedicated P&G I noticed no increase in FE. In my Saturn anyway, P&G w/ neutral doesn't yield much return, say at 40mph putting it in neutral reads 95mpg, in gear it will be roughly 82mpg. So, I assume it could help, but at the expense of added wear/tear on your transmission. EDIT: Thanks for the shout-out BEEF! Yes, the WAI has helped my FE tremendously! I love mine, and it's just a basic rendering. To be more efficient it really needs to be insulated and sealed better. I might add though, whereas Saturns are notorious for oil burn issues related to the piston rings, my oil burn has drastically increased over the last 3k miles and I'm wondering if feeding the engine hot air could be some cause for it. Maybe/maybe not, like I said, these engines are notorious for it and I plan on re-ringing just as soon as I get one of my other projects on the road. |
I tried the neutral coasting thing too. I saw a huge difference on the scangauge. I SHOULD have gotten 43MPG according to the scangauge for that tank and ended up with 36 or so. obviously something wasn't taken into account with the scangauge.
I think also it is a mixture of the fact that my eingine load is 25+ percent in neutral and the fact that my car will coast a long ways in gear. coasting in gear also nets me an engine load of single digits. the lowest I have seen is 7 percent. |
I've been shutting the engine off @ lights where I know I'm going to be stopped for more than 30 seconds on my current tank. We'll see how it goes. SG doesn't seem to be reporting anything spectacular for the tank.
-Jay |
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-Jay |
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