Estimate of mpg gain?
 

Hey all. For those that haven't read my introduction, I drive a 1994 Jeep Wrangler. It is the 4 cylinder, 5-speed model and has betwen 130,000 and 140,000 miles on it. When I first got it, it was averaging me anywhere from 13 to 15 mpg. Since the EPA estimates for it are 17 city/18 highway, I've been checking into the usual maintenance items and replacing as needed. Thus far, I've done the plugs, wires, cap and rotor. I plan to do the fuel filter and air filter within the next week or two.

Basically, my question is that if I manage to get the thing running peak again (approximately meeting the EPA estimates) about how much more of an efficiency/mpg improvement could I expect with the following mods?

• Partial grill block
• Air dam
• Synthetic lube in the engine, transmission and differentials
• Heat-resistant exhaust wrap
• Folding in or removing mirrors
• Airing tires to max
• Keeping highway speeds to 55-60 mph

That is pretty much my big list of ideas for the Jeep. I just wanted to see what you guys thought I could gain from that. Thanks for any and all help.

+2 mpg

What highway speeds do you currently drive, and how much highway driving makes up a typical tank? (Depending on your starting point & amount of hwy use, that may be where you'll get the biggest improvement.)

Normally I drive about 70 mph, and a typical tank is usually around 60% highway/40% city.

OK. Then "Keeping highway speeds to 55-60 mph" will probably give you the single largest % improvement of the items you listed (though they'll all help - don't get me wrong).

I'm guessing a 20% minimum improvement, combined. That would take you from 14-17 mpg, approx.

You should make a garage entry for the Jeep & start recording your fill-ups so we can see how it progresses.