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[El Tano]

Let's see if someone can answer this, becouse for it seems weird:
The car comes with 215/60 16 and the Temporary one that came with my car is 155/70 17. So when I put those numbers in the calculator I get this:

215/60 16 VS 155/70 17
CALCULATED:
Overall Wheel diameter in Inches: 26.157 vs 25.543
Wheel Circumference in Inches: 82.176 vs 80.247
Wheel revolutions per mile: 771.027 vs 789.566
Wheel revolutions per second @ 65MPH: 13.921 vs 14.256

NOTE: Changing the tire diameter CHANGES the SPEEDOMETER accuracy!

This ALTERNATE tire size will cause the 'Actual Vehicle Speed' to be 63.474
mph, when the speedometer reads exactly 65mph.

Or, when the 'Actual Vehicle Speed' is 65mph the speedometer will now read 66.563

Also, the ground clearance of the vehicle will change by inches -0.307

The overall diameter of the spare is smaller, now if you put the Temporary in the front, you are going to have two different sizes, doesn't this mess up the tranny???
I don' t understand why the don't put a full size tire...charge $100 more and the car, but give me a real wheel not a doughnut (cheap bastards, hahaha).....

So question is: Having a different size wheel doesn't ruin the transmission???