2.7l is weak, should I regear???

I have a 2000 Prerunner with the 2.7l and auto tranny. The truck is very weak off idle and gets bad gas mileage around town. A friend has a set of 4.30's I can use to swap out my 3.91's. My question is how high will my rpms be going down the interstate and how off will my speedo be? Thanks

 

I can't quantify anything for you but in general going from a 3.91 to a 4.30 your performance (acceleration distance) will increase, your fuel mileage is going to drop, and your highway RPMs are going to be higher.
If you're looking for a performance increase it might be worth looking into a good exhaust system, intake, hot ignition and high performance plugs and plug wires. My dad did a mild tune to his '98 Rodeo (4 Cylinder), it gave it a bit more oomph, he's happy with it. Better than messing with the rear gear in my opinion.

 

Thanks for the advice. I'd much rather look into exhaust and intakes then gears.

 

try this website http://www.grimmjeeper.com/gears.html

You'll have to look up the gears in your transmission, but it's seems pretty accurate

 

The math is really simple.

Current rpm times 4.30/3.91 or 1.1


If you are 2500 at 60 now you will be 2500 * 1.1 = 2750.

 

Thanks for the help. I'm adding cruise control here in a few days. I'll see if that makes a difference.

 

I have a 2.7 with automatic, and it has 4.56 gears from the factory.
Are you sure you have 3.91's? What is your axle code on the door jamb?

 

have you done a head to toe tune-up on the motor/vehicle?

 

The code on the door is B06A. From what I can tell, that means it has an 8" diff, 3.91's, and an open rear end. And no I haven't tuned it.

 

New spark plugs(platinum or iridium), Afe pro dry or K&N air filter. I bet you will feel a difference. Also, do the seafoam mod. 1/3 bottle in the gas tank,1/3 in the oil (pre oil change, ride on it for about 1000 miles to let it do some work) 1/3 bottle in the intake manifold. Ill try to find the thread on it for you.

 

I second the tune up. And if that's not sufficient the intake/exhaust options. . .

 

Usually only regear if you are running larger tires. Do a tune up.seafoam. aftermarket air filter. Your truck is just slow. Buy a v6 or v8.

 

http://www.tacomaworld.com/forum/1st-gen-tacomas/63790-seafoam.html
post 36!

 

Thanks for the seafoam link