New owner here.

Any thoughts on the best way to achieve MPG nirvana while accelerating away from a stop light?

Cruise control's Resume function seems to take a middle-of-the-road approach mainly working in the 3500-4000 rpm range -- in my limited experience.

 

::cringe:: Use your foot, and be like a snail.

Ok, that might be a little too slow for the Escalade behind you, but really, 2000rpm is a fairly respectable accel, and so long as you stay below ~2650, you're still delivering max torque to the wheels.

 

Thanks for the tip. I'll give it my best try......
Last car was a little black jet.... Acura Integra
So a hybrid is quite a culture shock for me <grin>

 

Acura integra = little black jet?

 

That cruise control is a gas-eater when you leave it on its own. Most of the high-mpg types here cringe at the thought of "3500-4000 rpm seems pretty reasonable for getting back up to speed." If you care about fuel economy, don't let the cruise control accelerate the car, and don't hit your resume switch until you're already at the speed you want. If you hit it a couple mph below your set speed, the car will still rev an extra 1000 rpm trying to race you back to your set speed (and we have to use the word "race" with this car advisedly to begin with).

As you play around with it, you'll find times when, say, your cruise is set to 65, your tach is sitting at ~1900, you encounter a slight rise, your speed drops to 64, and the car revs to 3500 to try to get you back that 1 mph. Whereas you could use enough foot to raise the revs to 2100 for the same amount of time and recover the 1 mph -- if you even cared; you could just maintain the 1900 revs, do 64 until the terrain itself lets the car return to 65, and never waste a drop of gas.)

The cruise in general will rev you 1000-1500 rpm higher than you need if you're driving manually -- because, driving manually, you don't mind tapping the battery, but the cruise tries not to; it's programmed to conserve as much battery as possible, because unlike you, it can't look up the road and see how long the hill is. If you need battery management on hills, use the cruise; if you need fuel economy, use your foot.

cheers --
doug

 

Just think of 2500 rpm as your new redline. you will be able to accelerate just fine with that. And stop using your cruise control if you want the most MPG.

 

There is some acceleration versus fuel economy data in tarabell's article. Personally, I try not to go over 2300 rpm unless I really have to. If I am going to be driving normally (no FASing), I will try hard to keep it under 2000 rpm during acceleration.

 

Great advice from all!
Thanks for contributing.
Easy does it is my motto now.

 

I've wondered about the "don't go above 2000 or 2500 when you accelerate" mantra. While I generally find it to be a fine prospect when you're at a stoplight on a relatively level road, I'm not sure it's the best when you're starting from a stop on an incline.

My main example (well, only example really - highly scientific here) is on my commute home I go through a toll when I'm exiting the highway. I have a Smarttag, but it's always late to register so I generally come to nearly a stop most of the time. Immediately after the toll is a rather steep grade I have to climb with no turning (since it's a split exit and my exit is much further down than the closer ones). Now, if I keep my RPMs below 2000 or 2500 I'm pretty much stuck at 35mph max speed for the duration of the climb, and on top of that the mpg meter stays stuck well below 50mpg, probably in the 20s or 30s, for the whole climb - frequently dropping my computer-measured average down by nearly .4 or .5mpg or more over the course of this hill.

However, if I gun the accelerator and get maximum assist, I can get up to about 45mph very quickly and essentially do a pulse and then glide the way up the rest of the hill without getting too far below 45mph for comfort (traffic does pile behind you on those toll exits). I don't lose nearly as much off my computer-measured average, and the glid obviously keeps the impg meter much higher for most of the climb.

Perhaps this is a special circumstance given the grade, as I've never compared the two methods from a stoplight on a flat road - mainly because I have always had the 2000 and 2500 rule pounded into my head. The only reason I tried it on the grade after the toll was because of the serious lack of speed or acceleration doing that method on a climb.

 

The easy does it philosophy has been around for a long time. It used to be "Drive like you have a raw egg between your foot and the accelerator" now it's a simpler statement of "stay below 2500 rpm"..... but.....

I've always wondered if that is really better than a higher rev to get up to speed sooner. All the following numbers are completely arbitrary and have no connection to anyone's current version of reality.

Given a higher acceleration rate (25 mpg) for a shorter distance (1/4 mile)

.25miles divided by 25 mpg gives 0.01 gallons of gas used.

Given a lower accelation rate (45 mpg) for a longer distance (1 mile) to achieve the same final speed.

1 mile divided by 45 mpg gives .0222222 gallons consumed which seems to indicate that it takes around 2 times more gas to reach the same speed.

Someday I may have the time to test this out.
Or... has someone already done this?