tire question (will 175/70/13 hurt mpg? 165/70/13 is stock)

[Ryland]

What are your revs at highway speed in 5th gear? everyone who is suggesting taller tires is starting out with a car that has pretty lousy gearing, where your gearing if I remember correctly is about the same as the CRX HF, so you're engine is already turning around 1,900 RPM at 65mph.

[mikehallbackhoe]

what do you think about running 165 70 13 on the front, and 175 70 13 on the rear?would it give more power to the drive wheels, and possibly better rolling resistance to the rear wheels?

[Ryland]

Do you need new tires? if you do and if you really want taller tires in the rear then I would put 155/80 R13 tires in the rear, the big draw back that you will get from having two sizes of tires on the car is that you can't rotate them.

[mikehallbackhoe]

the 175 70 13 tires on my car have decent tread, but are old and weather checked. I found a set of tires and wheels ,175 70 13, cheap on craigslist. but would prefer the 165 70 13 on the front. to rotate, I would buy 4 165 79 13 tires for my stock rims, and just rotate them on the front, and rotate the rears with the other set of rims with the 175 tires. it would actually make it easier to rotate tires, since I would need only one jack. if the 165 series would be better, I will just stick with a new set of them , and scrap this idea.