Tacoma Tires

New guy here, member of the over 60 set, first post.

I just picked up a 2010 Tacoma 4x4, reg. cab, 4 cyl-5 spd manual.

The prior owner put on 265/70 R17 tires.

I was wondering how this will affect gas milage and does it make the speedometer read wrong?

I don't plan on any wild off roading other than it will be handy in deer season. Plus I do live in snow country (usually) so it 4x4 will be handy then.

Debating whether to keep these clodhoppers or go back to stock tires.

tia

Neal

 

It seems to me that those 'clodhoppers' are of the small variety around here. A lot of guys actually run wider. I do not believe the upsize from stock affects the speedo significantly. I think there is a formula around the site somewhere that helps to calculate the difference . Anyone? I run that tire size in a C load range. I find they provide me with a much better ride quality.

 

Howdy and welcome. According to my handheld GPS, those same size tires on mine make my speedo read approx 2 mph low at 65. My mileage did decrease when I put these on, but I also levelled it (Bilstein 5100's set at 1.75) and am carrying a heavy cap with rack (drag) so I can't put it all on the tires. Now that I have an Ultraguage, I'm able to see what I'm doing and have been able to bring my mpg's back up to around 17 with 90-95% highway driving at 65-70 mph. I'm running an '11 AC/4.0l/6-spd.

 

It's about a 3.5% difference in height & speed over stock, which is about the amount my speedometer is off (reads high) when running stock size tires. Running 265/70R17 makes my speedometer read dead on with my GPS. I figured they would kill the gas mileage, but oddly enough didn't seem to make any difference to me. I have '07 DCSB V6, don't think it makes any difference though.

David

 

welcome!

should not change MPG by much at all. i’m going to a 265/75 r16 soon. witch i know is 1” taller than the 265/70R16.

 

didn't affect my mileage either. I'm still getting 18.5-19 city and 20-21 hwy

 

Remember its not the height but technically the circumference of the tire that changes the speedo readings. 2 pi r, or about 3.14159 times the height of the tire is your rolling circumference, give or take. There are lots of factors involved in mpg, like the weight of the wheel/tire, rolling friction, etc.

Try this calculator. There are lots of handy wheel and tire calculators out there. Just have to search:
http://www.performanceprobe.com/ind...nceprobe.com/misc/index.php?do=calc&page=tire

Check some tire sites also for good reviews. I use tirerack.com and discounttire.com. They usually have lots of customer reviews.

 

Actually it doesn't matter. The height of the tire (diameter) or the circumference, the % difference will be the same and therefore the % error will be the same.

%difference in height = % difference in circumference = % diff in speedometer.

No reason to calculate circumference unless it just makes you happy to do so.

David

 

You are right, but..its the rolling distance (circumference) that is a more precise measurement.

 

There are no measurements being made in this discussion. It's all calculated based on the tire size, multiplying the calculated tire diameter by 3.14, 3,140,000 (or any other number) doesn't change the precision of the calculated speedometer error at all. None. Zero. Nada. Zilch.



David