Tires: Jeep Liberty tires, stock rims, jeep liberty

Question
QUESTION: I have a 2003 Jeep Liberty that needs new tires.  It currently has P235 70R16 tires on the stock rims.  Can I put narrower tires on the existing rims to try to improve the gas mileage??

ANSWER: David,

With that size, you are pretty much not going to improve the fuel economy by changing size.  A better choice would be careful selection of the tire.

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QUESTION: I know it's not going to make a lot of difference-the the Jeep in only driven on city streets so don't need anything but highway tread anyway.
From the costs of tires I have checked on line, I can save a few bucks by going to a more narrow tire.  Could I go to a P215 or P205 on the rim?

Answer
David,

You need to match load carrying capacity.  To do otherwise is to compromise safety.

That means there is only one alternative to a P235/70R16 - a P225/75R16.  For practical purposes this really isn't a difference - particularly compared to the differences between tires.