MellonC00

When going to Plus 1 modificaiton on the wheel tire upgrade for the RX300, everone recommends the 235/60 - 17. I find that this should not be the case. Instead, I am going for the 235/65 - 17.

Of course, people say that this will throw off the speedometer and understate my mph. But will it really? I don't think so based on my research.

First, the number of revolution of tire for every 60 miles for the stock set up is 69254.4 while the revolution for the 235/65 - 17's is 70780.8 cuasing an under reporting of 1.32mph. In other words, when the speedo says that you are going 60 mph you are acutally doing 61.32 mph. But are you really?

Check out this article from Car and Driver. http://www.caranddriver.com/article....rticle_id=1906

It says that average Toyotas that CandD tested over the years have overstated the mph at 70 mph about 0.95 mph. That means that you'll actually be understating your mph by only 0.37 mph when traveling at 70 mph. And I'd say that's neglegible.

Just my two cents. (too much turkey and stuffing got to me.....)

ederny

Mell, one might also want to consider that a slightly smaller diameter will deliver a bit more torque to the ground - don't know if you can notice the difference, but going larger that stock could show a dercernable difference btw the two. Anyway, just be sure the 65s will fit under the rear shock tower.