Automatic Transmission

I have a 2001 chevy metro 4 cyl. with 13 inch wheels and automatic transmission. The engine rpm’s are running high at highway speeds. would a larger diameter wheel help this situation?

If the transmission isn’t slipping and is shifting into the top gear, then I suppose you might be able to get slightly better mileage with larger diameter wheels and the engine rpm will be lower. Keep in mind that the speedometer will be off. However, the performance will be off as well because you will have effectively a higher gear ratio.

If the car has always had high rpm at highways speeds, that is the way it was designed. I doubt that it is worth changing wheel size. However, if the rpm of the engine just started running high, you have a transmission problem.

Can you tell if the transmission is going into the highest gear? Does it have an overdrive gear that is not working or is turned off?

It does not have overdrive. It seems to shift into high gear.

If the transmission isn’t slipping and is shifting into the top gear, your Metro is running as designed. You don’t say how high the rpm is, but it is designed to run at this rpm level on the highway and there isn’t much you can do.

Thank You

It is not clear whether the engine has always run at high RPMs on the highway, or if this is a new sitation.
If it is a new situation, this is usually an indication of impending transmission failure, and larger wheels will not prevent transmission failure.

Can you clarify for us whether this is a new situation, or if the car has always operated this way?

That being said, there is a reason for those tiny wheels–namely tiny wheel wells.
It is very possible that larger wheels will not fit in the wheel wells on this car.

I just purchased this car so I am not sure if it has always run at high RPMs. I think I will have it checked by a mechanic .

The engine rpm’s are running high at highway speeds.

How do you know this is so?  What is the RPM and what do you believe it should be?