Smaller Tires

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Jul 13, 2005 | 12:10 AM

bigdaddyII

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From: Southern Louisiana

Smaller Tires

I had a set of 4 new tires given to me by my dad when we went to visit him this week. The only problem is that the tires are a little smaller than was on my truck. The size that was on there were 235/70/r16 and the ones that were just put on there are 225/75/r16. Not to much of a diffrence, but how would this affect my speed calibration, and will this minute size diffrence affect anything else such as gas mileage? The gear ratio on my truck is 3.55. Thanks in advance.

Jul 13, 2005 | 01:50 AM

RomerB2

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From: Bixby, OK

It's going to affect it a little bit but not enough really to matter. It will change your MPG but, only because you'll be not reading the right callibration and it will set your equasion (sp?) to be wrong. You'll be going slower than what your speedo says.

Jul 13, 2005 | 11:08 AM

460

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From: In the Middle

Your new tires, the 225/75/r16, are just a little taller than your old tires, the 235/70/r16. The "theoretical" height of your old tires is 29", and your new ones are 29.3"

It's possible that they may be the same height in real life though because when companies manufacture tires they are usually just a bit different in actual size from the stated size on the side wall. I think the height of the two sizes you have listed are close enough that you won't even notice a difference.

Here is a calculator you can use to figure out your tires height and width http://www.tyres1.com/calculators.html scroll down to "Metric Tire to Inches Conversion"