20-22mpg!

[FUPA]

That's what I am getting now and I am not driving like a a$$. I am about to change my spark plugs for the first time and I know that should help out the mileage a little bit, but what else could I do to help save money on gas?

[ThatsMeGC]

That sounds pretty good to me. I get about 300 miles per tank (city driving).

If you want better, I don't know check your tire pressure, get a bottle of fuel injector cleaner, typical stuff.

[dz]

I'm about 297 miles and am barely past half a tank.

Cruise control works wonders.

[slow6]

what, you cant keep your foot steady enough to keep it at the same rpms?
seems like the cruise control over-accelerates on climbs.

[HokieBird]

Might want to do wires, air filter, and fuel filter while you are at it.

I hit 34mpg last week on a mainly highway drive.

[dz]

I probably could keep my foot steady enough. Cruise control can do it much better than I would though, so I'll use that.

[bret_xi]

i'm at over 200 miles this tank and still at full.... my gauge is broke... [img]smile.gif[/img] lol

[Loochy88]

most the gauges on our cars are like that. theres a funny shape to the tank. when im about half empty im right at the full line.

[rhouse21]

Originally posted by Loochy88:
most the gauges on our cars are like that. theres a funny shape to the tank. when im about half empty im right at the full line.

Yup. Our tanks are roughly triangular in profile, so they little float in there doesn't do a great job of telling you exactly how much fuel is left in there.

Based on 8 years of driving observations, on my car:
Full line = ~3/4 tank
3/4 line = ~1/2 tank
1/2 line = ~1/3 tank
1/4 line = ~3-4 gallons (depending on time of day and/or phase of the moon)
just over empty line = ~2 gallons

...but I'm not sure that this is the same for other cars.

[Little G]

25mpg bishes! Dump some weight for better gas mileage.

g

[shenanigans]

hehe I hit 24 the otherday, and my car is a pig.

short shift, keep the revs low and only openen it up a few times. Its what I have been doing.


Or better yet get a slipping clutc, keeps me form giiving it too much gas [img]smile.gif[/img]

[SpeedingFirebird]

Originally posted by shenanigans:

short shift, keep the revs low and only openen it up a few times. Its what I have been doing.

Actually, it's keep the RPMs high. More torque means less fuel.

I don't know why everyone thinks cruise is good on gas. It's actually worse (as mentioned - because it over accelerates up hills). A steady foot with slight increases works best. I get 325 - 350 on a tank with the FB.

[Chris@Thunder Racing]

Here are some other ideas that may help also:

Whisper Induction Lid
http://www.thunderracing.com/catalog...vid=5&pcid=182

Hypertech Programmer
http://www.thunderracing.com/catalog...vid=5&pcid=151

Magnaflow Cat-Back Exhaust System
http://www.thunderracing.com/catalog...&vid=5&pcid=53

Chris

[rhouse21]

Originally posted by SpeedingFirebird:
Actually, it's keep the RPMs high. More torque means less fuel.

Math time again:
When cruising at steady highway speed, your car is at a state of equilibrium, meaning that the force of the engine pushing you down the road is equal to the force exerted by the aero-drag trying to slow you back down to a stop.

In geek-speak:
F = Aero Drag = 1/2 *(air density)*(coef of drag)*(Area exposed to wind)*(velocity)^2

Power is defined as energy per unit time, so...
road horsepower (the amount of power your engine needs to put to ground at a certain speed) = Aero Drag * Velocity

Saving a bunch of ugly math, it takes roughly 30 road hp to sustain most cars at highway speed.

Engine HP can be defined as Torque * RPM, so to the first order SpeadingFirebird's assertion about revs vs torque might seem correct, but we have to remember that for a given cruise speed, no matter what the gearing is, the engine must still be outputting the same amount of HP to the ground or else the car would be accelerating. Increasing engine revs for a certain power setting does decrease engine torque, but the product of the two still yields the same amount of horsepower.

You can look at this another way:
Each ounce of fuel contains a given amount of energy. (This is referred to as the fuel's energy density.) Assuming your engine is working right, it should always need roughly the same amount of fuel to produce a given amount of energy. Since you only need a set amount of energy per second to cuise at highway speed, a perfect engine would always consume the same amount of fuel regardless of engine rpm.

...But real engines aren't perfect. Real engines produce a lot of internal drag. They have large, heavy pistons with abrasive pistone rings that scrape constantly agains piston walls and accessory drive belts that suck away power to pump fluids, compess refrigerents for a/c systems, and produce electricity for power hungry convenience items, such as stereos and defrosters. All these things add a lot of drag to the engine and the amount of drag increases as engine revs increase. In other words, it takes more energy to keep your engine spinning at 5,000 rpm than it does to keep it spinning at let's say 1,800 rpm. So, the higher you keep the rpms, the more internal drag your engine has and the less efficient it is. This is why big engines usually have overdrive gears that drop engine revs to rediculously low levels to boost economy. It's also why a lot of super-efficient cars are going to CVT's (continually variable transmissions) so that they can constantly change the gearing to keep the engine at its most efficient rpm.

As for cruise control:
Cruise control usually helps mileage because it can (in most situations) hold the engine at a steady speed better than a person can, so you spend less time accelerating and changing speeds. That's it. Esentially it just helps you keep engine revs lower for a longer time, which can average out to be a significant energy savings over time. There's no magic here. And while our cruise control does seem to over-achieve on hills, it usually averages out over time. Yeah, it makes you feel like an old lady while driving, but it does help you to keep the revs low.

(Don't you love engineers. :D )

[Ender2664]

I keep GREAT gas milage records for my car so i know EXACTLY what my car averages, daily, weekly, monthly, i am anal like that. I get 20-21 on ALL city and I get 30-32 on all freeway. I have NEVER gotten worse than 18 mpg even when i beat the hell out of the car and make my 130 mph passes all over the freeway.