Would this reduce pumping losses?

[EcoCivic]

I have been thinking of a way to reduce pumping losses. I have a few ideas, but the most practical may be to accelerate with lots of throttle, maybe half to three quarter open, but not open enough to go into open loop, but still shift at the same low RPM. I would try it, but I have an auto It could even be implemented into P&G. What would the problem with that be? There surely must be a problem with that. What is it?

[EcoCivic]

Originally Posted by Old Tele man

Nope, you got it.

So how many MPG could be gained by doing that? Would it cause excessive engine wear?

[Stubby79]

What years is your civic, or whatever you're driving?

[EcoCivic]

Originally Posted by Stubby79

What years is your civic, or whatever you're driving?

It is a 2005 Civic and I put a VTEC motor in it.

[Stubby79]

Originally Posted by EcoCivic

It is a 2005 Civic and I put a VTEC motor in it.

New stuff, like that, you'll only be able to change the shift patterns with reprogramming, assuming that's possible.

Older stuff with a separate transmission control module, you could fool it in to not thinking the throttle is open much.

Even older stuff with a kickdown cable, you could mess around with even easier. Well, if you could reprogram without much effort, that would be even easier.

[Ecky]

That's a better way to accelerate, yes. Once you're up to speed though, your pumping losses are pretty much a function of gearing, unless you pulse and glide. On the highway, many on here will accelerate under high load, then throw it into neutral (or shut the engine off) and let the car coast for a while, rinse and repeat.

In my Insight pulse and glide helps very little, since it has a small engine with very tall gearing - it's already running at high load most of the time. In my previous car, which had very short gearing and a large engine, I found that if I was very determined with my pulse and glide, I could improve my highway economy from ~30-35 at steady speeds, to 50+ by pulsing and gliding.

[teoman]

Does pulse and glide also yield good results with diesels / turbo diesels?

[Mustang Dave]

Originally Posted by EcoCivic

I have been thinking of a way to reduce pumping losses. I have a few ideas, but the most practical may be to accelerate with lots of throttle, maybe half to three quarter open, but not open enough to go into open loop, but still shift at the same low RPM.

That's how I accelerate with my Mustang. Most of the time.

My numbers aren't too bad for a 4-liter V-6 in a 3500# car.

[Ecky]

Originally Posted by teoman

Does pulse and glide also yield good results with diesels / turbo diesels?

Less than gasoline. You still save a bit on parasitic losses from accessories and some friction, but at least with older diesels, there's no throttle plate. Probably not worth the effort in most cases, unless you're going for records.

[hayden55]

Accelerate with your torque converter fully locked up at the least and you'll see a gain.