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I pumped up my tires yesterday to find that they had dropped into the mid 30s due to the lower temperature and possibly a little leakage. So I took the plunge and went straight for max sidewall. This morning's commute through the slush was depressing, but all the stops came out this afternoon as I was driving around town. I focussed on improving how I accelerate since that's where my numbers really take a dive. I upshifted super early to get into 4th as early as possible, and managed to slow my rate of acceleration to the point where the scangauge shows 32mpg+. Fifth gear comes at around 30 on flat roads, at which point I can coax it to gain speed at 45mpg and over. That's crazy! Even more crazy is that I once found myself cruising up a slight grade at a constant 30-35 in fifth with the scangauge reading 50MPG! I didn't even know that was possible, especially considering that it's 45F at most out there. The upshot is that I got stuck at every single light from the bank to my apartment (I count 4 in 2 miles) and still pulled off nearly 39mpg on the segment.

What it really boils down to, IMHO, is that we really need to get to know our cars. The little details of their strengths and weaknesses are where we find out where to focus our efforts and refine technique. In no way do I have the hypermiling thing figured out, but the potential that I see in my machine is shocking. SOOO glad I bought this thing last summer :D.

ya if you noticed in lower rpms, its very easy to press more accel by accident causing your MPG to spike lower as your lugging the engine to speed. Back off a bit it, and it spikes higher but you'll also notice its very easy to lose speed (bleeding) so keeping a balance is pretty important.


Since your accord is heavy, you should take advantage of coasting as much as possible, then put it into 5th if you know your going to stop. So that fuel injectors turn off instead of putting it into neutral and then braking to stop. Since your going to slow down anyway that method will at least allow you to save gas without turning off the engine since if you know the light will turn green in such a short amount of time.

Brick, was it you who determined that the injectors are not shut off in your carwith foot-off in gear? Wasn't your gph consumption higher than in N?

I'll doublecheck my car tomorrow, but I am reasonaby sure that for the HAH, the injectors are shut in gear.

Like you said, its about knowing your car. Some cars do shut the injectors.

Yeah, according to the scangauge my injectors don't cut off in gear. If the engine is really warm it might inject less fuel (0.2GPH instead of 0.3GPH) but the vast majority of the time the engine actually consumes more fuel (0.4GPH or more). I thought about it some more and I think it might be due to the ULEV engine. They might have been worried about the cat getting cold if the car coasts too far without burning any fuel. It's obnoxious because I'm always hunting for the point at which the engine is pulling rather than pushing so that I can throw it in neutral. It's a very fine line and often tough to find. I also hate having to use the brakes so much since I don't engine brake.

Brick, the SG always assumes the injectors are on. If you want to know for certain however, display loop mode. Accellerate to a given speed with the engine fully warmed, stay in gear and be above 1500rpm. Lift fully off the throttle and you should see it switch from close to open loop. That means your injectors have shut off. All Hondas do it.

Aha. Thanks for the tip! I'll check that out tomorrow. My brake rotors thank you for pointing that out.

I would go out on a limb and say that *any* modern fuel injected car (maybe 15 years old or less) will shut off its injectors on a coastdown.

^ correct, that bug is scanguage related. I knew about it so even though scanguage is telling me I'm consuming more gas in 5th than in N, that's not true, if your foot is off the accel in gear = NO GAS.

The open loop/closed loop check seemed to work. If I shift into gear to slow down it does switch to open.

I stumbled upon this old thread and just wanted to note for the archives that this bug has been corrected in the latest scanguage firmware. When coasting in gear mpg is shown to be 9999.

How can I tell if my 93 Saturn has fuel cutoff? It isn't scanguage compatible. I drive over a mountain pass weekly to ski, and a significant amount of engine braking is needed. But there are spots where I could choose to clutch or leave it in 5th. If I have fuel cutoff, leaving it in gear, feet off the pedals, would be a better choice. I'll be catching up to the cars ahead of me either way. Is 1,500 rpm the typical min rpm for fuel cutoff, regardless of manufacturer?

I have noticed that engine temp drops during the long descent, but I don't know if that means no fuel or simply less fuel with good airflow over the radiator. Temp holds pretty steady for the rest of the drive.