The Insight tire is a special tire, but for each tire manufacturer's brand/series of tire, a narrower tire is lighter. Find good tire mass and diameter information at.

https://www.tirerack.com/

https://www.tirerack.com/tires/Spec.j...e1=yes&place=0

An even narrower tire is available, 155-80 R13. It has a diameter of 22.7, as opposed to a 175-70R13. The 155 tire weighs 1 pound less.

Upping to larger tires is essentially the same as getting a longer geared transmission. The downside of this is that your odomoter/speedometer will be affected as well. Your odometer/speedometer is calibrated to stock tire size, so you might end up being a little off (3% or so) so you might have to adjust your MPG figures each time you calculate them.

Then again, I upgraded to 185s (175 stock) and my speedometer/odometer is right on (I tested with a GPS unit).

I would go with LRR tires or more narrow tires before thinking of getting new rims.

The 155-80-R13 you mentioned are 14 lbs. The 165-65-R14 Insight tire is one pound less, 13 lbs.

https://www.tirerack.com/tires/Spec.j...l=Potenza+RE92

https://www.tirerack.com/tires/Spec.j...e1=yes&place=1

This 155-80R13 tire is only 12 pounds. Neener, neener, neener...... LOL

But not LRR. :D