265/65/17 or 265/70/17 for highway tires?

Sprung vs unsprung weight and then adding in rotational weight. The following is quoted from another car forum... I will not be held responsible for spelling, punctuation and grammar mistakes, but it is well explained:

"you really have 3 different classifications of weight.

sprung weight

unsprung weight

rotational weight

sprung weight is anything that is on the car that is carried by the shocks/springs. so trunk, seats, engine, etc...

unsprung weight is everything that touches the road before the springs. so wheels, brake rotors and calipers, hubs, and half of the shock itself.

rotational weight is the stuff that rotates. here there is a bit of a mix between sprung and unsprung weight. your driveshaft is rotational weight, but it is also sprung. your wheels are rotational and unsprung.

ideally, your suspension will work best with the least amount of unsprung weight (quicker response, less inertia), so better handling. your car will accelerate best with the least amount of rotational weight. so wheels, brake rotors, drive shafts, light weight clutch, etc. reducing sprung weight helps everything, but not quite to the effect that the other two will.

so if you look at it that way, taking rotating, unsprung weight off the car will help the most. wheels, brake rotors, lug nuts, tires. there is no set number like a lot of people pass around like "1lb of rotating mass is like 5lbs of regular mass". thats just not easily quantifiable because if you take a pound out of a tire, its going to have a much bigger effect then taking a pound out of a driveshaft. the reason is the tire has a much higher moment of inertia then the axle does."

 

So saving a few pounds in tire weight is worth more than the benefit of a larger tire?

 

Depends on how you use your truck. If you do a lot of steady highway cruise with very little acceleration once you get up to speed, the tire weight won't make much of a difference.

 

Use stock size, your MPG is worse with larger tires. It is all for looks.

 

Tire for tire, when I was looking to go from 265/65/17 up to 265/70/17, the slightly larger 70 series tires were generally cheaper. Turns out the 265/70/17 is a standard size Silverados (and maybe other full sizes) use. The 265/65/17 used on the Tacoma is not as common of a size.

 

Like I mentioned before, I've found the same thing. This is one of the reasons I'm considering it.

 

I've been considering the same thing. To my understanding the 265 70 17s are about an inch taller then the 265 65 17s. Does that mean a slightly higher ground clearance too?

 

From what I've read, yes. About an inch of extra ground clearance

 

1/2"

 

This.

 

1" taller tire = 1/2" more ground clearance.

Height increase divided by 2, always.

 

Well, my question fits right into this thread. I have a 17' TRD OR with 16" stock rims.

I would like to go 17x7" TRD Pro 4Runner rims, but don't want to go the standard 265/70/17.

What's the narrowest tire I can put on the 7" wide rim? Reason I ask is because, more contact on the ground=more rolling resistance = worse mpg.

I think this plays just as much into the equation with tire weight, etc.

 

I would be more concerned about the tread. i know my best mpg in a truck was with michelin ltx m/s2 tires. i hit 9.7 L/100km (24mpg) in a 99 4runner that was rated for 13 L/100km (18mpg). Haven't gotten close to there with my 17' yet which is rated for 23mpg (10.2 L/100km)

 

*I'll be running Michelin LTX AT/2 which already have a better rolling resistance than the stock Goodyear Kevlars.

The best mpg I have had with the stock tires was highway, driving conservatively and did 26.8mpg.

 

If I can afford it I would like to get the Michelin defender m/s. I'm thinking about going with the larger diameter mainly for looks and to fix the speedometer. I've been looking at coopers lsx also mainly for looks. I don't need an all terrain but I want a tread that won't get me stuck in wet grass.

 

Wondering your thoughts here: https://www.tacomaworld.com/threads...e-trd-pro-wheels-all-stock-suspension.766232/

I'm basically debating just about the same thing. Going with 16" for a new set of wheel and tire combo vs 17" . I can actually get the 17" setup cheaper than the 16" , but out of necessity I will be doing a lot of highway driving this summer with my Tacoma, which with gas prices as they are, will add up quickly.

 

Honestly since you’re going to be doing a lot of highway I would keep to stock size tires. If you choose those 17” rims, 265/65R17, or if you go with 16” rims, 265/70R16.

Upsizing tires will do nothing but hurt mpg’s in my experiences. I drive extremely conservative with mpg’s always in mind. Looks are by far the biggest benefit IF you don’t do legit off-roading…(pardon my grandiose here) but I have went up/down plenty of rocky and sometimes icy hunting trails with stock size Michelin LTX’s without fail.

 

17" wheels have more tire selections. but either is fine, get whatever rim design you prefer.

265/70/17 are larger than 265/65/17 and 265/70/16, so your MPG will be a bit worse, and speedometer off about 2-3%.

 

I should have clarified that the primary reason for selection of 265/70/17 to mount on the 17" wheel was based on the fact that it is _very_ widely available and indeed is cheaper than the 265/70/16 tire by a good margin (and is what the 4runner TRD pro uses)

I've seen quotes on this site about this. Seems a lot of domestic trucks utilize 265/70/17 so that may be the reason for the cheaper price.

 

depending on your suspension and wheel set up, it may have minor rubbing on mudflaps / etc. it will look better. if you get efficient tires it wont affect your MPG too much.