City Driving is Killng my FE [ Archive] - GasSavers.org - Helping You Save at the Pump

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

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

Swap a d15b7 in.

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.

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 }:)

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

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

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 ~~

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!

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.

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.

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.

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.

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

So can I turn the ingnition to "engine off" then back to "on" without freaking out the ScanGauge?

only one way to find out! and you won't freak it out. depending on the car's ODB protocol, it will either go to sleep and take 10-20 seconds to re-initialize when you switch the key back on (during which time fuel, speed & distance data isn't logged), or it will remain on processing merrily away.

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

1 - if i had to use a/c (don't have it in my car), i would manually switch it off when accelerating, and switch it back on only when cruising or decelerating. (my car's "a/c" is a wood bead seat cover. keeps the air flowing behind and beneath, and no sticking to the seat.)

2 - as for rate of acceleration, my recent 80+ mpg segments have been achieved with the *slowest* practical rate. though i haven't done any tests to see if quicker is better.

though it stands to reason that quicker would only be better if your cruising speed is going to last for a long time. if there's a stop in your near future, you won't reap the hypothetical benefit of quicker acceleration because your cruise/coast won't last long enough to make up the difference.

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.

that may be, but the next big question is which decel technique, D or N, yields the longest coasting distance?

my car's injectors shut off when decelerating in gear, but it's a fact that coasting in neutral with the engine idling is far more efficient because the car goes *significantly* further decelerating in neutral than decelerating in gear.

ymmv. that's why you have a scangauge!

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.

that may be, but the next big question is which decel technique, D or N, yields the longest coasting distance?

my car's injectors shut off when decelerating in gear, but it's a fact that coasting in neutral with the engine idling is far more efficient because the car goes *significantly* further decelerating in neutral than decelerating in gear.

ymmv. that's why you have a scangauge![/quote]

This is how the ScanGauge rates as one of the best inventions of all time: 1. Sliced Bread, 2. Eli Whitney's Cotton Gin, 3. ScanGuage. This thing is awesome. I already have a friend buying one to monitor his MPGs.

Now, the N or D question has been considered. For my ECU, long grades would easily be engine shut-down + N or engine-on + D -- not a whole lot of compression holding back. Short-distance would have to be engine on for me with the auto. There's a significant loss in FE when I coast, in N, with the engine-on. D seems to yield a better benefit. Engine off showed 9999 mpg, which is as good as it gets on the device (flipping back to ingnition "On") keeps it alive. I just have to weigh the FE vs. starter wear. Too bad there's no way to kick-start an automatic or else I'd be coasting all over the place.

Let's get crazy folks...since the rear wheel is on an independent suspension, a half-shaft and CV setup would be way too complicated to have an electric motor as a movement assist. Picture a swing-arm mechanism on a shock absorber and gear-drive attached to a small rubber tire and an electric motor that could be moved to meet up with the car's rear tire at a stop. When you need to go, then engage the electric motor (probably need some serious batts in the back (weight :-( ), then after the car is started and put into D, the swing arm is activated to move the drive tire away from the car's tire.(perhaps automatically). At higher speeds, the arm could be moved manually so the little tire meets back with rear tire and the motor could be switched to a generator to charge the batts, completely independent of the alternator. Of course with suspension movement, it would have to be robust and shock absorbing.

1. I wonder if there's enough room back there for such an apparatus.
2. What kind of motor and current is required?
3. Would the rubber drive tire have enough rubber-on-rubber traction to achieve movement with the car's rear tire (rain or water would probably render the idea moot)?
4. Am I crazy?

Feel free to answer all questions, including #4.

RH77

#4 seems about right. Don't spend a lot of money on stuff to increase mpg by 2-3.

Damnit, so I should stop coasting to a stop in neutral, damnit!

Thanks for that.

Anyway, once I killed the car and left it in drive, about as fast as I killed it it started back up. Ooooppps.

Damnit, so I should stop coasting to a stop in neutral, damnit!

Thanks for that.

Anyway, once I killed the car and left it in drive, about as fast as I killed it it started back up. Ooooppps.

Not sure what your injectors do on low-speed decel (with OBD-I), but for me, they tend to cycle down when when I coast in drive. At N, the MPG goes down around 50mpg from 150mpg to 100 or so. It takes more energy (fuel) to idle the car than it does to use the energy of momentum to slow you and use it to turn the engine. Since your car is very light, you're mileage may vary.

RH77

I just have to weigh the FE vs. starter wear. Too bad there's no way to kick-start an automatic or else I'd be coasting all over the place.

when was the last time you had to replace a starter motor on ANY car?

for me it was probably 16 years ago on a vw rabbit. i think i changed 2 or 3 rabbit starters, which says something about rabbit starters vs the rest of the world (i owned a small herd of rabbits when i was in h.s./university). other than that, i've never changed any other car's starter, and i've probably owned around 20 different old, beat up, used cars.

even if you did have to change a starter, aren't they a dime a dozen for that engine? from all the swapping going on , i'd think in the unlikely event you wore it out, you could get a replacement pretty cheap.

i say: live a little. coast! all over the place.

His engine, actually, is very desirable, so it might not be the easiest thing to pick up. His tranny sorta sucks, but never the less, it's tough to get at too cheaply. I'd have trouble finding a free one (I have two free starters for my car, :p)

His engine, actually, is very desirable, so it might not be the easiest thing to pick up. His tranny sorta sucks, but never the less, it's tough to get at too cheaply. I'd have trouble finding a free one (I have two free starters for my car, :p)

That should be a pretty good pick-up line. "Hey, you know I have a desirable engine :wink:"

SVOboy you're right, though. The starter may be robust, but the transmission is what it is. When it goes out a 5-speed's going in there, but that'll even probably be a while. I have heard of Toyota starters going out often, but not Hondacuras.

i say: live a little. coast! all over the place.

I don't know if they still make it, but do you remember that Coast soap? They had a catchy theme song about it waking you up and getting you going in the morning. That's what will solve the gas problem:

A national advertising campaign:

to music: "Coast! It will save you gas. Coast! Now Exxon's kissing your ***..."

RH77

here's something to think about

60 km/h in N = 110 mpg
50 km/h = 90 mpg
40 km/h = 70 mpg
30 km/h = 50 mpg
20 km/h = 30 mpg
10 km/h = 20 mpg

any speed = engine off 9999999999 mpg

my engine displacement is 1.7 liters by the way.

my engine displacement is 1.7 liters by the way.

Sorry to hear that Phil. You are not alone. I am stuck with my 1.5L fat pig of an engine. Id be happy with a 3 cyl 1.0L.

Wow your engines suck (gas) I get 50-60mpg at as little at 15mph in neutral if the engine is warmed up and idling. What I also do is try to keep the speed a little higher when coasting as in 30mph in a 25 zone so that I get even higher mpg - the quicker you get there in neutral the less gas I burn keeping the engine turning over. I do seem to see the idle increase at higher speeds in neutral weird huh? like it will not come down to 650rpm until I stop for a few seconds. I don't see much difference in MPG in gear or in neutral coasting until the rpm gets over 2500-3000 rpm then the mpg decreases (90mpg vs 150mpg).

I guess the stopped in neutral vs stopped in gear makes sense because of the lower idle speed burns less gas.

I've been utilizing the N at lights process a lot lately. On the ScanGauge, I can see the manifold pressure go from approx. 5.5 to 4.5, so it looks to be using less energy to keep out of D at stops (Same with A/C - 6.5 down to 5.5). Would the gallons-per-hour feature show more info, I wonder? I'll try it today...

RH77

His engine, actually, is very desirable, so it might not be the easiest thing to pick up.

i was assuming the starters are interchangeable. so you could get a starter off one of the less desirable disposable free honda motors. maybe a bad assumption, however.

It's not a bad assumption, you might be confused by the fact that we call everything honda when in fact honda and acura made dramatically different US engines from 92-00. SOHC and DOHC stuff is largely incompatible.

Remember the old crank start on the front of Model-T's. A quick turn and it started. Dangerous but effective. I'm sure the compression would require much more effort these days. How about this...on automatics, something to engage the motion of the moving wheel to kick-start the engine. Well, come to think, a starter would be cheaper and maybe easier than all of that. Nevermind

RH77
...Thought I'd post it anyway

as recently as the 80's, an imported car was available in north america with a crank start (as backup to its electric starter). anyone but me remember what it was?

Wow yah my dad used to have a Toyota wagon when we lived in Detroit, and I totally remember seeing all sorts of "other" wagons around town. I'd point them out, and really "see" them. Notice how you do that once you own a type of car?

Anyway someone in my subdivision owned this sweet looking volvo wagon that had nothing but glass in the back. I swear I seen a crank tucked in the front grill area.

not sure about volvo, but it was on a car from another northern country: the lada had a crank.

It's not a bad assumption, you might be confused by the fact that we call everything honda when in fact honda and acura made dramatically different US engines from 92-00. SOHC and DOHC stuff is largely incompatible.

Really? as far as I know, there is no "acura" in japan, it's a Honda NSX, Honda Integra (no rsx's there). There is very few engines that are "Acura" or "Honda" specific

My car has a B-16 from a 2000 civic in it, this same engine has been in several other honda/acura products all over the world, and the block is used in almost all high performance honda/acura products (not the V-6 cars, Accord, Prelude) for most of the 90's Decade, B-16's, B-17's, B-18's, and even the slightly more unique B-20 all share a common block, swaping motors from one to the other is only slightly more complicated than swapping for the stock one. I can swap in a motor from anything from an Acura Integra Type R, to a Big CRV, to a JDM 1988 CRX, with no problems. This is one of the reason honda's are so often tuned (and stolen).

The Sohc (D-series) and Dohc (B-series) are very different. They share very few features at all with each other, but then again, who want's a SOHC anyways ;)

1.

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?


RH77
Try this with the A/C : Since the A/C is such a power-consumer (have you watched your RPMs sag when the A/C is turned "on" at idle?), try turning the A/C 'off" when you want to accelerate from a stop- then turn it back "on" after cruising speed is reached. Less drag while the engine is working to gain some speed (overcoming inertia)... and the interior heat won't build that much. :thumbup: ?