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97 Brighton, 4x4
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Discussion Starter · #1 ·
I'm driving from Salt lake city to Mt Hood for some summer snowboarding (700+ miles) and I'm wondering if you guys could give me some tips to try and get the best millage out of my car on the way. The car is a 1997 1.8L Brighton coupe.

Should I reset the ECU before I go?
What speed will yield the best millage?
Would you try and coast down hills (ie taking it out of gear and then putting it back in with a rev match?)
Ac or no Ac? (mine is not running well, the compressor is sucking major juice and squeals momentarily when the clutch engages)
Could I do anything with tape and card board to make it more aerodynamics?:blol:

I really hope I can at least get 32 mpg but I don't know if the car is running good enough to accomplish this.

Thanks for the help, I hope to have pics of my adventures.
 

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1994 Aegean L, 1998 Panda!
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Get rid of all the excess tool you haul around in case you break down and the two spares to carry.

Use good gas (not ARCO) and only fill half a tank or so. Take an extra 2 gal gas can with gas for reserves. Check all tires for nails and PSI.

Take other seats out...

If I were you, I wouldn't use me compressor. What if it catches and the belt snaps?
 

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1999 2.5RS
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674 Posts
Resetting the ECU would be a good idea, just make sure to drive conservatively.

If you can, just use the cruise control and see if you can keep it under 3k, depending on the slope of the road you're on.

Don't coast down hills in neutral, when you do this your car is still idling and using gas. If you keep the car in gear and coast downhill the injectors will not be spraying any fuel AFAIK.

I would keep the AC off if you can, if it gets too warm turn it on for a little bit to cool down.

Make sure your tires are properly inflated.

Do an oil change beforehand and take care of any other maintenance, air filter, fuel filter, spark plugs ect...

Only bring what you need, if your trunk is full of crap you won't use on your trip ditch it before you leave.
 

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99 Aspen White Coupe
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443 Posts
There are lots of tips to increase economy, but first I'd do everything I can to get it running as well as possible. Bad sensors and things really eat gas. Resetting the ECU probably wouldn't hurt either.

I'd bump up your tire pressure a bit. Maybe something in the range of 38f/34r. Too much will ear your tires badly, so I'm not sure on a perfect number.

AC is a hard call. Some people think the aerodynamic drag from open windows negates teh gains from not having the commpressor running. I can't tell you since my AC doesn't work.

DON'T COAST OUT OF GEAR!!! This will actually hurt your mileage. Reason being that modern cars don't use any gas (or damn close to none) when coasting in gear. You'll use more by letting your engine idle. Just coast in gear.

As always, the biggest determinate of your economy is your driving style. Accelerate gently and brake early. Shift early too, but not to the point of lugging the engine, that also hurts mileage.

Ideal speed for economy is around 55, but that's a bit slow for most of us, so don't worry too much, just don't fly along at 85.

I don't know about imprving aero... I've heard claims thata good wax helps a little, but I don't know if it's true.

That's all I can think of at the moment. I'm sure others will chime in with good info.
 

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Generally I hear around 50 MPH yields the best mileage. Any faster and wind resistance is more and more. I wouldn't reset the ECU, it's not really needed IMO.

If you can, close the windows and use just the vents blowing (no AC). I'm not sure how hot it is where you are, but that would be best I'd think to get rid of that wind resistance with the windows down and also no using the AC.

For coasting downhills, you can try it, but it's a heatedly debated topic. I've tried both and found no difference in mileage between keeping it in gear or neutral. But then again, I have an automatic.

Keep those tires pumped up a little over what you normally run, but not over the max stated on the tirewall. If you can fit your snowboard in the trunk or backseat, it would bed better than fitting it on the roof due to wind resistance.

Mainly highway fuel economy is majorly based on wind resistance and the speed your traveling. Extra weight plays more into city driving since your starting and stopping a lot, not so much with highway stuff. So doing things like taking out the rear seats is kinda pointless. Now, carrying cement blocks for fun wouldn't be a great idea for any fuel economy.

Edit: As for the person above talking about waxing... I've hear that can increase mileage like 2MPG or something crazy like that. I'd give it a shot if your looking to do everything you can and have time.
 

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The reality is that your engine is the major culprit of mileage. Friction between the pistons and cylinder wall eat close to 90% of the energy produced by the engine, so get a good synthetic oil and a new filter and change it. Tires, weight, air resistance, drivetrain losses, etc., all account for less than 10% of the power loss.

Beware of inflating your tires if it is going to be hot. Your tires pressure increases with heat and friction, and you can easily have a blow out.

Best mileage can be obtained at around 35mph. Clearly that is not viable, so remember that the air pressure on your frontal area of the car is CUBED as speed increases, so 50 mph will obtain better results than 60. I'd drive 60 just because you will likely only save pennies for a 10mph speed difference.

Myth busters disproved the A/C versus windows argument, so do whatever is more comfortable. And the belt sequels because it's lose or old, to go adjust it or replace it! :rolleyes:
 

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1994 Aegean L, 1998 Panda!
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^ RS, you want him to run synthetic in one of these things? :rotflmao:
He'll be lucky to have any oil left in his car at the last leg of the trip there unless he had been using synthetic.
 

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2001 A.W. L
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Control of your right foot is what is most important.. Everytime you step on the gas you are using gas, the further you push the throttle down the more gas you are using...

My dad gets much better MPG's when he drives my car because he never gets into WOT..

(and this wont cost you any money ;) )
 

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Keeping it in closed loop help a lot. In closed loop the car will be targeting 14.7 to 1 AFR which mean all of the gas in the combustion cycle is burnt. You can do this by only using 1/3 throttle when accelerating and not going above 3k rpm. Also by drafting a large vehicle you can greatly increase mileage. In tests done by mythbusters they found 40% or more decrease in fuel consumption while drafting a semi.http://mythbustersresults.com/episode80
At higher speeds air resistance plays a good part. Thats why a 200hp car can go 150mph but it takes 400 more hp to get 50 more mph to break 200mph. The air resistance is not linear. It increases at an increasing rate as you go faster.
 

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ok terrific.
'95 STi RA rep, rhd yo!
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I never understand why people say to up the air pressure in your tires. You may save a few bucks in gas, but the last time I checked, four new tires aren't cheap. The sticker on the door suggests tire pressure for the best wear pattern, IIRC 32F/29R.

Keep the car in gear going down hills unless engine braking slows the car down too much. If you put the car into neutral, the engine is still idling and using gas. If you keep it in gear, the momentum of the car is keeping the engine going.

It sounds like you need to tighten your A/C belt. I would suggest just running the A/C. Yes, it does use power that could otherwise be put to the road, but driver comfort and avoiding fatigue should more important than saving a few cents. Your windows being open will act more like a parachute at highway speeds too, the noise may lead to distractions (tractor trailers at speed), and gives the chance for debris to make its way in or out of the vehicle.

Other than that, just don't drive like a douche and stick to the speed limit. You would be surprised at just how much your mileage is affected by how much you're on the accelerator.

I follow my own advice, keep an eye on the suggested tire pressure, keep my speeds to 5 over the limit out of habit, and I use my A/C regularly. I average about 30mpg, mostly highway, with the occasional backroad bombing.
 

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99' red subaru impreza wagon
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i got 33 mpg in my L going 60 at max on a recent trip
 

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Keeping it in closed loop help a lot. In closed loop the car will be targeting 14.7 to 1 AFR which mean all of the gas in the combustion cycle is burnt. You can do this by only using 1/3 throttle when accelerating and not going above 3k rpm. Also by drafting a large vehicle you can greatly increase mileage. In tests done by mythbusters they found 40% or more decrease in fuel consumption while drafting a semi.http://mythbustersresults.com/episode80
At higher speeds air resistance plays a good part. Thats why a 200hp car can go 150mph but it takes 400 more hp to get 50 more mph to break 200mph. The air resistance is not linear. It increases at an increasing rate as you go faster.

thats why i said closed loop lol cause i wasnt sure which loop it was (long day @ work)

if the afrs are stoich it uses Less gas then when its closed
 

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1994 Aegean L, 1998 Panda!
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+1 for drafting hummers!
Forget all of that. He could just buy a few of those bungee cords and attack to the back of one of them. Just make sure you have a few guns and ammo so if they get ready to take an off-ramp that you don't want, you can either shoot them, force them to keep going, or shoot the bungee cord.
 

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Try to draft behind big stuff like tractor trailors and huge SUVs. Coast to any stoplights. Make sure your tire pressure is good, maybe a little higher than normal. If the a/c works fine, use it, bc drag coefficents increase at highway speeds with the windows down. Aka, its more economical to run real a/c than 460 a/c( 4 windows down, 60 mph)
 

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I think if you google hypermilling you might find some (far out) suggestions. Is that the right term?
 

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97 Brighton, 4x4
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Discussion Starter · #18 ·
Wow, I never thought there would be this much responce. I changed my oil / filter last night in prep. I didn't use synthetic though I used some high millage formula, mostly because it's dirt cheap. Also I rotated and presurized my tires to right under 40psi. I might decrease that though. Does anyone know what speed 3k is on a Brighton. There is no tack so I can't tell. Does it have the same gearing as the other types of impreza's?

Thanks for all the feedback guys.
 

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97 Brighton, 4x4
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Discussion Starter · #20 ·
Yeah, I'll prob. lower it before I go. I hate my crappy pressure gage.

I think there is something wrong with the AC and that is why It squeals. It's not so much a squeal as a chirp or even a cchhhhhh mmmmnnnn :lol: But there is another thread on this and I think I need to recharge the system or my compressor is going bad.
 
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