Mods To Avoid To Keep Gas Mileage?

gotta choose mpg

Keep your 195/192 therm. hotter =leaner

Pull the screen out of that stock mass air and have it ported

Put on a good set of free flowing exhaust

keep the injectors they are good UP TO 300 hp

I love my 3.55 gear. but a 3.08 is just fine for a cruiser.

93 hatch , 26.07 mpg on the hiway at 80+ mph with over 135,ooo on the clock. Thats what tunning is for!

hell no your avarage stock 4 banger isnt good in snow any REAR WHEEL DRIVE CAR IS NO GOOD in the snow. yes s/c will help g/m but a cam will not and no need for bigger injectors or regulator.

All the advice on injector size is for the changes you mentioned in the original post; if you supercharge you'll obviously need some way of delivering more fuel to the engine.

There are plenty of rear wheel drive cars that are good in the snow, but the Stang with it's front-heavy weight distribution and lots of torque isn't the easiest to drive in slick conditions. Most newer rear wheel drive cars have traction control which makes them much better to drive in snow. One of the most popular cars in the history of the automobile was rear drive and it was great in the snow - the VW Beetle. And for a good 40 years our friends in Sweden drove rear wheel drive Volvo's in the snow quite effectively. Granted, front wheel drive is better, and all wheel drive is almost uneventful in the snow, but there are plenty of rear wheel drivers that get by ok when the road gets slippery, provided you get appropriate winter tires on them.

don't know how far your going but my .02

cam= bad miliage (the ho camshaft seems to be a phenomenom of good miliage and torque range, so id stay with it)

exhaust - depends on foot position but a slight decrease in mpg overall

intake - too many varibles but overall difference wont be much at all

ceramic coating pistons and heads=free power and an increase in miliage

fuel system - just support for induction. assuming everything works correctly

heads - the more fuel efficient ones are the hi swirl combustion like the e6 head and most aluminum aftermarket. but this all again depends on the position of the right foot

a supercharger shouldn't affect driability since it's not always in boost...

You can go pretty far with mods and still keep relatively stock mileage. You have to take torque into consideration more than power, though. Torque is usually made with induction that has high velocity like GT-40P heads and an Explorer intake. After that, the cam has a huge bearing on economy not just because it allows more air and fuel in, but also due to where it puts the power band in relation to your car's setup and your driving habits. My cam's power starts at 2500rpm, but at 55mph where a stock Mustang tends to make best mileage, I'm at 1500rpm. I'm always below the cam's efficiency range and as a result, lost about 8mpg. 65mph gains back about 4mpg on that loss. If you're really anal about it, stay with iron heads since they lose less comustion energy to the cooling system.

On the other hand, I commute in a '91 Civic STD hatchback(gutless wonder, 92hp & 1.5L) and last fill up I calculated 37.5mpg average. Not highway only, but average city/highway/canyon road driving. I'm going to do a tune up to see if I cant break 40mpg.

If you're one of those drivers that likes to get to the speed limit as soon as possible (like me) then gears will improve your gas mileage as you will require less pedal action to get to speed.

Mod to avoid as stated are a cam. More than anything you need to keep a good tune (ie good plug wires, fresh plugs, fresh fuel filter, clean injectors and a working fuel pres regulator) these are things that when worn or go bad cause your mileage to go down the crapper. Some other things neglected in the fox stangs that cause mileage to go to crap are the ACT and the use of a thermostat too low in temp.

3:73s will rev up quicker causing you to use more gas unless you shift it quickly, 3:08's for good gas milage!

TheUser said:

a supercharger shouldn't affect driability since it's not always in boost...

Click to expand...

who buys a supercharger to not put down there right foot?? Just b/c it sits there and looks pretty.


Rule of thumb is the more mods ( Power ) you add to a car the less your MPG will be. As your power goes up it requires more fuel. If you you only have 2 yrs of school left Id advise saving money for the next 2 yrs for mods and then buying what you want b/c YOUR NOT GOING TO BE ABLE TO MOD THE CAR AND IMPROVE/KEEP MPG THE SAME.

"Rule of thumb is the more mods ( Power ) you add to a car the less your MPG will be."

Unfortunately, it's not that simple. What hurts mileage is when the engine is modded in a way that it becomes less efficient in the rpm range where you operate on the street most of the time. Most naturally aspirated mods shift the power and torque rpm peaks up the rpm range. While the engine is making more power overall, it's usually making less power and torque below 2500-3000 rpm than it did before the mods. And most street operation occurs below 3000 rpm -- that's why many modded naturally aspirated cars get worse mileage.

It can be avoided or even improved, but you have to be really careful. I wasn't interested in building a bunch more peak power - the stock HO had plenty of beans for my needs. I did want to lighten the car though so aluminum heads were a must for me. And I wanted to mod in a way where we didn't lose any power or torque over the stocker through the entire rpm range. We were successful at that - a big piece of credit for that accomplishment goes to Buddy Rawls who did my custom cam. It makes at least 270 lb-ft of torque from about 1600 rpm all the way to 5000. And I've got about 55 more HP at peak than stock. My car weighs about 3270 lbs. with me in it (190 lbs.). It's got 3.73 gears with a shorter tire than the Stang - kind of like a Stang with 3.90 gears. And, well there's no way around it, the Volvo's aerodynamics are comparable to a brick's. Nevertheless, I consistently get 16-19 mpg around town, and 23-25 on the highway (best single tank of 26.8mpg). It ain't 35mpg, but for the performance level I've got available to me, it's pretty good gas mileage. And with 8K-10K miles on the mods, after consistently checking fuel mileage, it's PICKED UP about 1mpg from when it was stock on both the highway and in town. You can mod without significantly impacting mileage, but you have to be thoughtful about it.

Supercharging and turbocharging (like additional compression ratio) usually improve the efficiency of an engine - so better mileage (if you keep your foot out of it) is not uncommon in milder applications.

see there we go 16-19 city is good for a stang, 23-25 is a hell of alot better then a mustang that gets 10mpg because i know some of them out there get that and people just dont know why. i just dont want to do all these go fast goodeys and end up with something that it costs 5 bucks to go to the store 3 miles away.

does any know what kinda gas mileage that ford gt40 crate motor gets? not advertised but acctual, cause it "says" 345hp

There's lots of debate as to how much power that motor will actually make - but the 345HP rated motor has the X heads and the B cam. It's not gonna be very strong below 2500 or 3000 rpm - I suspect it would not be the most user friendly motor fuel mileage-wise around town.