[MetroMPG]

Moral of the story: obviously... tire choice can have an enormous impact on vehicle efficiency!

Stuff I learned:

• I was surprised how much better the RE92's were - not only did they have the best result overall, but they also had the biggest improvement when looking at the difference between each set of tires.

• I was surprised to see the big, beefy Michelin snow tires in 3rd place. With lots of deep-siped, blocky, squishy treads! (Then again, we know some snow tires can have LRR qualities - remember Chang Ho Kim's modified CRX winning the AMEC mpg rally with Nokian winter boots on?)

• The spare tire/donut performance surprised me. Part of me hoped they would have magical properties. Instead they were awful.

• PSI over 50 seemed to make little to no difference with the RE92s:

The next day I did a test of tire pressure vs. rolling resistance using the RE92's in the same parking lot. I went from 20 to 70 PSI in 10 PSI increments, 3 runs per increment. From 20-50 PSI, there was a measurable improvement each time. At 50, 60 & 70 PSI, there was no significant change in finishing position - the ending 9 chalk marks (3 PSI x 3 runs each) were mixed & clustered together along a 4.5 foot line.

I've done a test like that before: www.metrompg.com/posts/tire-pressure-rolling-resistance.htm