City Driving is Killng my FE

[rh77]

I've been getting great mileage (great for me = 40-50 mpg) out on the highway at 57 mph. The only problem is, I spend the other half of the time in city traffic, stop and go, sit and idle.

Mileage-wise, 80/20 Highway/City
Time-wise, 50/50.

Aside from buying a Hybrid, what can I do to my car that I haven't already tried to improve city mileage in the automatic? I've altered driving style, acceleration, less go-pedal all-around. I have noticed, once the TC kicks-in, it's like magic. FE increases dramatically, then less pedal is required. Can you alter the TC action manually, or do you have to be in top gear? I've noticed that sometimes it kicks in in 3rd before 4th like revving up a hill (hill-logic control) and the 4000 RPM trigger kicks the TC in, then once level ground is reached, a TC-engaged 3-4 ensues and a hard shift is realized.

Hmmm, what to do...

RH77

[SVOboy]

Ain't much you can do with the torque converter. Too bad your engine is so ****ing powerful,

Swap a d15b7 in.

[Compaq888]

for city you can only do 2 things. Remove weight for better accelaration and have an idle stop feature while stopped waiting for a green light. Those 2 draw the most fuel. The car doesn't require a lot of fuel to drive the same speed(freeway) that's why it gets such high mileager on the freeway. What it does require a lot of fuel is accelarating from a dead stop. It has to push all that weight to rolling speed.

If you don't want to do either then when you see a red light from far distance then start slowing down early, that way when you get close to it you are already rolling and it will require a lot less gas to get back up to speed.

[rh77]

Replying to SVOboy:

If 140hp is that powerful, then why did it feel so slow when I first drove it? I mean, slower than my '96 DX Manual (106 hp so you don't have to look it up or call it up from memory).

Engine Swap = Easy Way Out
Other vehicle management = challenging and perhaps cheaper and easier.

If I hear d15b7 one more time, I'm leaving the site and buying a Yugo (make it two - one for parts).

RH77 }

[rh77]

Originally Posted by Compaq888

for city you can only do 2 things. Remove weight for better accelaration and have an idle stop feature while stopped waiting for a green light. Those 2 draw the most fuel. The car doesn't require a lot of fuel to drive the same speed(freeway) that's why it gets such high mileager on the freeway. What it does require a lot of fuel is accelarating from a dead stop. It has to push all that weight to rolling speed.

If you don't want to do either then when you see a red light from far distance then start slowing down early, that way when you get close to it you are already rolling and it will require a lot less gas to get back up to speed.

I've implemented the coast-more theory, so the weight would come down to "not easy". Probably the first place I'd start is the wheel size and weight, but how much can help? I'm not gutting the car, either. Wer're talking daily driver here, and what isn't needed has already been taken out. Maybe I've hit the wall, and be happy with 28-36 variable mileage.

RH77

[thisisntjared]

your mileage woes are because it is a b series. like compaq said. easiest way to help this is weight.

[philmcneal]

in your case abuse N and don't use the brakes. ANticipate, predict and conquer the mpg.

But with those with sticks, 50 mpg segments in the city baby! Just find the roads with hills, DISTANCE IS NOT A FACTOR if you can make up that distance with the engine off. Its all in the roads ~~

[JanGeo]

hey do you burn more or less gas in gear when stopped or neutral?

I make up a lot of mpg in city driving by coasting - pulse and glide baby - it works!

[MetroMPG]

1 - get that scangauge yet?

2 - i have to agree with the previous 2 posts. i would have titled this thread "city driving has boosted my FE" since i started using (engine-off) coasting. in city driving segments i have begun to see mpg figures that are impossible to achieve at any steady highway speed.

Originally Posted by rh77

I've implemented the coast-more theory

time to implement the coast-even-more theory! pump up your tires and take phil's advice to coast instead of brake (and switch off the car when safe). each time you brake, take it as a sign you could have coasted longer. of course it's all dependent on traffic, but you have control over what route you drive.

[rh77]

Originally Posted by MetroMPG

1 - get that scangauge yet?

2 - i have to agree with the previous 2 posts. i would have titled this thread "city driving has boosted my FE" since i started using (engine-off) coasting. in city driving segments i have begun to see mpg figures that are impossible to achieve at any steady highway speed.

time to implement the coast-even-more theory! pump up your tires and take phil's advice to coast instead of brake (and switch off the car when safe). each time you brake, take it as a sign you could have coasted longer. of course it's all dependent on traffic, but you have control over what route you drive.

1. Oh yeah! I love the ScanGauge -- it even works on my rental car experiments with the engine displacement adjustment. I keep my eye on that thing very frequenty. So can I turn the ingnition to "engine off" then back to "on" without freaking out the ScanGauge? (although I move the ScanGauge between vehicles so often, so I can't really track an entire tank of my own car -- the device is mostly for monitoring on my own cars). Also for the A/C, is it less effecient to catch back up after re-start? I can get a couple of minutes of cool air on engine-off throught the evap coil.

2. It's getting to the point where the A/C is required simply for the humidity and the heat is building. Is there a secret to acceleration from a standing start? With the automatic I'm trying to decide if slowly accelerating is more efficient than a little more quickly getting up to a powerful rpm (2500), and modulate pedal pressure to get up to target speed upon which coasting is available. As far as the route goes, I have a huge hill to accend to get up to the highway, and with the logic-control on the transmission controller, it won't shift to a higher gear until a high RPM is achieved or level ground is reached. You really have to get up to at least 55 to merge or get into some trouble. It's a 2 turn-lane system that merges into 1, so everyone is competing for the lane (slow accelerators get the sqeeze). Anyway, I'll try the engine-off technique more and see what we get.

To answer JanGeo's question, the car gets much better mileage in D when the engine is on for decel -- N forces more fuel to maintain idle.

Thanks...

RH77