Tire Size....

[fuzzy dice]

My 2001 Yukon has 265/70/16 Michelin's on it...they need to be replaced soon...my thought is to go to a slightly taller (75) tire for better gas mileage...I know it will throw off my speddo slightly but I cna live with that given the gas prices...

Anyone have any thoughts on this plan?...

Also, I am just about at 100K so I plan to put in new plugs...I read NGK TR-5's work well...I believe I read to gap them to .040...is this correct?...TIA..

 

[Polecat]

a 265/70/16 is about 30.6" tall, and a 265/75/16 is about 31.6", so you gain about 1".

 

[foxie]

but I cna live with that given the gas prices...

Anyone have any thoughts on this plan?...

..

Come to the UK, it's over $9.00 a (US) Gallon now :cryin: you'll appreciate what you have..

Aside of that, with a 75 profile (all else the same) the rolling circumference of the new tyre will be very slightly more making your speedo read 3.4% too slow, ie at if your speedo reads 60mph, you'll actually be doing 62mph cant see it having much affect ? Pumping the tyres up harder may be a better option ?

 

[ugachs24]

Come to the UK, it's over $9.00 a (US) Gallon now :cryin: you'll appreciate what you have..

Aside of that, with a 75 profile (all else the same) the rolling circumference of the new tyre will be very slightly more making your speedo read 3.4% too slow, ie at if your speedo reads 60mph, you'll actually be doing 62mph cant see it having much affect ? Pumping the tyres up harder may be a better option ?

My 2004 Tahoe had OEM Bridgestone P265/70/17's on it until April and I wanted to go with a little larger tire so I went with LT275/70/17 Wrangler Silent Armors and it dropped my city mileage from 14 to 12 instantly but my highway mileage stayed at 19-20. They ride and handle great but killed the gas mileage.

 

[fuzzy dice]

Thanks guys...my idea is not to go wider which will negatively affect gas mileage due to increasing the rolling resistance...I am thinking a taller sidewall will actually take a little gear out of the vehicle thereby running a little lower rpm thereby using a bit less fuel, mostly on the highway...I can live with the small speedo difference...

 

[road1will]

Thanks guys...my idea is not to go wider which will negatively affect gas mileage due to increasing the rolling resistance...I am thinking a taller sidewall will actually take a little gear out of the vehicle thereby running a little lower rpm thereby using a bit less fuel, mostly on the highway...I can live with the small speedo difference...

I just went to 265/75s and my mileage did go down a bit. generally going to a larger tire is gonna hurt your mileage.

 

[Dianne Skinner]

If you don't want to do the math, go to:

http://www.miata.net/garage/tirecalc.html .

All questions answered there. Good luck.....

 

[JennaBear]

A taller or wider tire will negatively effect your MPG as others have stated. Then again, having an SUV will negatively effect your MPG!!:lol: