More mileage?

[RICHARDO]

Engine braking involves using the gearbox to slow down the car instead of the brakes. It can really only be done with a manual transmission.

 

[1X83Z]

It can really only be done with a manual transmission.

I do it frequently with Tiptronic.

It can also be done on a standard automatic transmission if you shift into a gear lower than 'drive'.

 

[RICHARDO]

Ah, thanks for correcting me, never tried it with a standard auto (And I'm not rich enough to be around a car with Tiptronic ).

Wouldn't it hurt the slushbox though if you put it in a lower gear when it's in motion?

 

[niky]

No AC is best. What you want to do is either keep the blower on or the recirc off so you can have fresh air blowing through the vents once you're up to speed.

Alternatively, if it's just too hot to live without AC, slide the thermostat to the warmest setting bearable and leave it there.

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You can engine brake on anything, as long as it's in gear while you're slowing down, that's engine-braking. It just doesn't make sense to do active engine-braking (or whatever you call it), where you downshift to keep the revs up and maximize engine-braking. Just let it coast down in a high gear and shift to N when you're almost stopped.

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I'm not the best eco-driver out there, but I get decent numbers... best I've gotten so far is about 20-25 km/l, but that was in a diesel Focus, a Prius and a Honda Fit... so that probably doesn't count...

 

[Orion]

No AC is best. What you want to do is either keep the blower on or the recirc off so you can have fresh air blowing through the vents once you're up to speed.

Alternatively, if it's just too hot to live without AC, slide the thermostat to the warmest setting bearable and leave it there.

I lost 3 out of 15 mpg on the highway with the a/c on.

 

[neanderthal]

Alternatively, if it's just too hot to live without AC, slide the thermostat to the warmest setting bearable and leave it there.

if the AC is on it doesnt matter what the setting is for the temperature. compressor doesnt care. it may cycle on and off a little less but its not really going to make that much difference.

what i do is switch on to maximum when im coasting and stopped. 0mpg is still 0 mpg when you turn on the ac. if you are coasting then you are going on momentum, not using the engine to power the AC. and powering the AC is less than powering the car.
turn on the EC feature and recirculate before you move.

 

[Perfect Balance]

I lost 3 out of 15 mpg on the highway with the a/c on.

How are you getting 15mpg? You drive a bus, and I think anything there is at a much larger scale than you would have in your car. Fuel consumption, aerodynamic drag, using the a/c.

Unless you mean your MR2, but with those kind of numbers, something is wrong with your car.

EDIT: 15mpg in a bus making me think hybrid though, which is even more things that play a factor.

 

[Joey D]

Ya 15mpg is what the Blazer gets...in the city.

 

[Orion]

How are you getting 15mpg? You drive a bus, and I think anything there is at a much larger scale than you would have in your car. Fuel consumption, aerodynamic drag, using the a/c. 15mpg in a bus making me think hybrid though, which is even more things that play a factor.

Yes it's a 40ft hybrid bus with CVT.

 

[Perfect Balance]

Yes it's a 40ft hybrid with CVT.

So theres the hybrid part, then the part where there's always a different amount of weight in it. Then there's the boxy shape, and the huge amount of windows that can be opened to produce even more drag. Then there's also the huge amount of a/c needed to cool it, which could possibly be a huge electronic unit on the roof in the first place.


I think a bus doesn't work in this thread. There's just too many factors that play a HUGE role in the mpg on a bus.

 

[Orion]

So theres the hybrid part, then the part where there's always a different amount of weight in it. Then there's the boxy shape, and the huge amount of windows that can be opened to produce even more drag. Then there's also the huge amount of a/c needed to cool it, which could possibly be a huge electronic unit on the roof in the first place.


I think a bus doesn't work in this thread. There's just too many factors that play a HUGE role in the mpg on a bus.

But I always have closed windows & ac off, the ac makes engines sound terrible. Plus most of the time I'm the only person inside, I am just the driver that is filling in for absentee's or taking buses for engine swaps/maintainance/testing.

Back on topic: I still loose mpg with ac on an auto ford focus. About 10-15% more fuel per gallon.
Edit: ac=24mpg no ac=27mpg.

 

[ROAD_DOGG33J]

Tire pressure is critical. Even a small amount of underinflation can seriously deplete your fuel economy. I like my tires stiff so I tend to inflate them a few pounds over the recommended pressure on your door plate. For most cars the recommended pressures are going to be in the 30-32 psi range. I usually run 36-38 cold, but you should run at least the recommended pressure.

How would this affect tire wear. On my car, the recommended is 29 for the front and 26 for the rear. Once, I looked at them in the car park and thought I had a flat tire, but it was the same on both sides. I didn't notice any abnormal wear so far.

what i do is switch on to maximum when im coasting and stopped. 0mpg is still 0 mpg when you turn on the ac. if you are coasting then you are going on momentum, not using the engine to power the AC. and powering the AC is less than powering the car.
turn on the EC feature and recirculate before you move.

So you use less gas over time for AC when you are stopped?

 

[Thatman]

Wouldn't it hurt the slushbox though if you put it in a lower gear when it's in motion?

Depends on how fast your going. Anything above of what the can handle=BAD.

 

[niky]

RE: stopped: no, what he means is, you're wasting gas anyway, so might as well have the AC on. I don't agree with this personally, but AC while coasting down is a good idea. The idea of leaving it on while stopped might be more valid for larger engines with more torque, though, as the drain isn't as significant. That 10 hp drag the engine experiences with the AC on is more significant for a 110 hp engine than a 200+ hp engine.

Never downshift the slushbox into a lower gear when it would place the engine speed above the converter lock-up point (which is somewhere between 2000-3600 rpm, typically), it'll play merry hell with your converter... which costs more than your typical clutch.

Underinflation = premature tread wear, and in extreme cases, worn sidewalls. If economy is important, you always slightly over-inflate. It lowers rolling resistance and makes the handling better, to boot.

 

[neanderthal]

an engine at idle is making what? ~10-100 hp right, depending on how big it is and so on.
well, when its stopped, its getting exactly zero miles per gallon. (niky alluded to his in his last post) you're not increasing your economy. if anything, youre consuming fuel and getting nowhere. decreasing fuel economy. and where's all that power going. nowhere. its becoming heat and going out your tailpipe.

so turn on the AC then. it might take a few hp to drive the compressor, but youre still gettin zero miles per gallon. and now instead of the fuel becoming heat and going out your tailpipe, its also cooling your cars interior.

since we measure fuel economy for cars in miles per gallon this is where you get the benefit of using AC. if we measured it in gallons per hour like most stationary machinery (generators etc) perhaps a different tack would be better. but thats not the case here, is it.

seems simple. im wondering why i have to continue to elucidate.

 

[Famine]

an engine at idle is making what? ~10-100 hp right, depending on how big it is and so on.
well, when its stopped, its getting exactly zero miles per gallon. (niky alluded to his in his last post) you're not increasing your economy. if anything, youre consuming fuel and getting nowhere. decreasing fuel economy. and where's all that power going. nowhere. its becoming heat and going out your tailpipe.

so turn on the AC then. it might take a few hp to drive the compressor, but youre still gettin zero miles per gallon. and now instead of the fuel becoming heat and going out your tailpipe, its also cooling your cars interior.

since we measure fuel economy for cars in miles per gallon this is where you get the benefit of using AC. if we measured it in gallons per hour like most stationary machinery (generators etc) perhaps a different tack would be better. but thats not the case here, is it.

seems simple. im wondering why i have to continue to elucidate.

While static, you're getting 0mpg. Correct. However, that's instant fuel economy, not average.

Say you do 30 miles at 30mpg, get stuck at an excessively long traffic signal and use up 0.1 gallons while idling, then do 30 more miles at 30mpg. Your average is:
60 miles / 2.1 gallons = 28.57mpg

Now do the same but turn on your aircon when static. You use 20% more fuel while waiting - 0.12 gallons. NOW your average is
60 miles / 2.12 gallons = 28.30mpg


While you weren't moving, your instant fuel economy didn't drop - it was zero in both situations. But your average fuel economy suffered by use of aircon.

 

[neanderthal]

i get that part.
you do consume more fuel. thats a given. but youre less likely to affect your consumption than if you were to turn on that AC when you tried to accelerate from that long traffic light ro while you were cruising even.

the best time to turn on the AC is when the engine is not doing any work. and by work i mean propelling the car. thats the point that i was getting at.

 

[neanderthal]

question for all.
how often do you turn off your car at a traffic light?

theres one when im leaving work which will be red for 5 minutes. if i roll up to that as it turns red. ill normally turn the car off especially as i will have just started the car after it sat for 8+hours. still cold, higher fuel consumption.

if the car is warm already i'll leave it in neutral and shift to drive when the light turns green.

 

[Joey D]

Don't you use more fuel by starting the vehicle then just leaving it run for periods of something like 10 minutes? Maybe someone can elaborate on that a little, it's just one of those things you hear in passing.

It just doesn't seem overly safe to sit there with the motor off either.

 

[Roo]

Ignoring fuel consumption for a moment, wouldn't it be better to leave the engine on to warm up nicely whilst no stresses are being put upon it?

By the by, does no-one know how to use the edit button anymore? It's not just you, neanderthal, it's just I was replying anyway.

 

[ROAD_DOGG33J]

Don't you use more fuel by starting the vehicle then just leaving it run for periods of something like 10 minutes? Maybe someone can elaborate on that a little, it's just one of those things you hear in passing.

It just doesn't seem overly safe to sit there with the motor off either.

On some site about saving gas, I read that starting your car uses the same amount of gas as idling for 1 minute.

 

[Jim Prower]

Well, It's a Montero, guys, it's not gonna get fantastic milage. a couple things I can think of...

(1): It's been said over and over: ease off the gas. Yours truly is guilty of being a pedal-masher, and I bet I could get 30MPG out of my Nova's carb'd 1.6 if I just eased off. Instead I'm hovering around 20.
(2): The Autozone Stop. get a good tire pressure guage, some injector cleaner, fresh oil, (Yes, fresh oil: When was the last time you changed it?) a new air filter, and anything else you think your car needs. Tranny fluid, and diff fluid, too. I'll bet you haven't changed those recently.
(3): Modification: This is a toughie. Personally, I think the only modifications one could really make to increase fuel economy are (A) an overdrive transmission and (b) taller final drive. sometimes Cold Air intakes claim to increase fuel milage. I'd be wary about this.

AVOID LIKE THE PLAGUE any sort of "Fuel Milage Booster" like those pills and such: It's snake oil.

Stil, at best, you're only gonna get maybe 20MPG max on the highway. 'tis the nature of a big, off-road ready SUV.

 

[Duke]

How would this affect tire wear. On my car, the recommended is 29 for the front and 26 for the rear.

If you seriously overinflate them, they will wear in the center more quickly than the edges. If they're underinflated, the outside edge wears first. However, a few pounds higher than recommended probably won't hurt your tire wear and might even help it. If the tire is rolling over less, it will likely wear more evenly across the contact patch.

On my Neons the alignment shop always made me sign a waiver about tire wear when I told them I wanted -2 degrees of camber. They swore it would make the inside edges wear out. In reality what it did was make them wear evenly across the face rather than the outside edges wearing first.

 

[ROAD_DOGG33J]

Should I add the same amount to the fronts and rears?

 

[racegeek]

also the proper fuel might give ya better mileage. i dunno about US and the rest of the Europe, but here Shell sells V-Power fuel, which is supposed to be better. I saw an article about it and it is supposebly proved to give 15 km more per tank.
also i tested it once and if my fuel gauge didnt sink so fast than with regular gasoline i fill up elsewhere. concider that!

 

[JCE]

The petrol the US gets is bad. Expect no difference on a normal car going from 87 to 93 octane.

I just can't help thinking that a Montero just idn't going to do much better than a combined 16~18mpg in mixed driving. And thats if its driven like a little old lady.

 

[RICHARDO]

Although you're right on our gas being pisswater, (especially regular)there is a difference in performance. Regular dosen't burn nowhere near as good as the higher octanes. Which causes the engine to misfire, (Even my grampa's Ford Escort Estate got engine knock from it.) causing lower performace and in the long-term damage to your engine.

The fuel economy difference might be small, but the quality of the gas is not.

Doesn't your car knock when you use regular?

 

[opendriver]

Well, It's a Montero, guys, it's not gonna get fantastic milage. a couple things I can think of...

(1): It's been said over and over: ease off the gas. Yours truly is guilty of being a pedal-masher, and I bet I could get 30MPG out of my Nova's carb'd 1.6 if I just eased off. Instead I'm hovering around 20.
(2): The Autozone Stop. get a good tire pressure guage, some injector cleaner, fresh oil, (Yes, fresh oil: When was the last time you changed it?) a new air filter, and anything else you think your car needs. Tranny fluid, and diff fluid, too. I'll bet you haven't changed those recently.
(3): Modification: This is a toughie. Personally, I think the only modifications one could really make to increase fuel economy are (A) an overdrive transmission and (b) taller final drive. sometimes Cold Air intakes claim to increase fuel milage. I'd be wary about this.

AVOID LIKE THE PLAGUE any sort of "Fuel Milage Booster" like those pills and such: It's snake oil.

Stil, at best, you're only gonna get maybe 20MPG max on the highway. 'tis the nature of a big, off-road ready SUV.

1. I did ease off the gas and did notice a good increase in mileage

2. Right now, im broke, so getting my oil changed is going to have to wait for about a month or so

3. I leave overdrive on all the time, and plan on getting a K&N filter and a cat-back exhaust system soon. I also heard that putting acetone in your gas gives you 10-20% increase overall in mileage, but there have been reports of it killing injectors, so im staying away from that.

And yes, it does knock on regular

 

[Perfect Balance]

3. I leave overdrive on all the time, and plan on getting a K&N filter and a cat-back exhaust system soon. I also heard that putting acetone in your gas gives you 10-20% increase overall in mileage, but there have been reports of it killing injectors, so im staying away from that.

And yes, it does knock on regular

Um...Doesn't overdrive not let it get into 4th gear or something like that so it's not constantly shifting when towing or going over mountains?

And stuff that boosts performance usually doesn't help with gas mileage, I don't think a catback will help.

 

[niky]

Power mods help up to a point... by removing some restrictions, you allow the engine to breathe more freely, which means you can pull harder at lower rpms.

But that's up to a point... once past that point, it negatively affects fuel consumption.

Acetone is a hit-or-miss thing. I have a friend that did documented testing, but he found the savings not worth the hassle.

You could go for a lighter oil to improve economy... but it depends on what your engine will take. Older engines will sometimes drink lighter weight synthetics because of worn seals.

Otherwise, the "Autozone stop" as suggested, is a good way to go... if your tires are nearing the end of their life, you can replace them with some low-rolling resistance Michelins... but this depends on you. I put a set of "energy saving" Michelins on my pick-up, and while they work a treat, I'm not sure the braking and cornering compromises are worth the savings.

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@Road_dogg: depends on your car. Go by the door sticker and add 3 psi to that. If it starts making the center of your tires wear faster, pump it back down to just 1-2 psi over standard.

There's no universal pressure balance. Some of us like harder fronts as it helps handling, but some applications (trucks and SUVs mainly) require harder rears for load carrying.

And tire construction has a big effect on ideal pressures, too.