gm-17" wheels

ky-kurnell · November 2, 2003

can anyone tell me if you will get any more clearance by going to a 17" wheel, although the 17" with a 265/ 70/17 tire on it the overall dimenions are less than the 265/75/16 , trying to decide if the 17's are worth it, also do they fill the whell well anymore than the 16's. any input would be appreciated greatly.

Also do you have to reprogram the dealers in Fl. are about useless when it comes to any type of knowledge about their product.

Thanks

Red 'rado · November 2, 2003

I show that the 265/75/16 has a 31.6 inch outside diameter. The 265/70/17 has the same identical 31.6 inch outside diameter. This choice of 17 inch tire will allow you to use a larger wheel without any affect on the speedo, etc. so there is nothing to reprogram for the change in tire size. Since the tires are the same diameter will will not gain any ground clearance either.

Will it fill the wheelwell better? No, because the tire is the same outside diameter. The effect of the slightly larger wheel looks good though. I went from the stock 16 inch wheels to 17 inch Escalade wheels on my 03 silverado. The larger size and the chrome looks much better than stock in my opinion.

MyBigToy · November 2, 2003

You will actually gain 1/2" of ground clearance at the axle because of the 1" larger wheel diameter. You have less tire sidewall and gain the extra clearance at the wheel.

MBT

RidesGuy · November 3, 2003

I just put on the 17" GMC wheel/tire option on my 2003 Sierra Z71 and I think they look great. The 16" polished option is getting outdated and it is time for a change. The ride height did increase slightly, maybe an 1" or so, because the seat of my pants has to be raised slightly now to get into the truck.

wandell · November 3, 2003

Red'rado is correct, you gain no ground clearance by changing wheel size. Taller tires give you more ground clearance, not larger wheels. For instance a 33x12.50 tire on a 15x10 inch rim will give you more ground clearance than a 265/70-17 on a 17x7 inch wheel because the 17's only have a 32 inch tall tire.

frdfandc · November 3, 2003

The way you figure out the overall diameter of the tire is this.

Tire size is 265/75R16 - the width of the tire is 265 millimeters wide

the number 75 in the tire size is the aspect ration. This means that the side wall height (from tread surface to rim) is 75 percent of the width of the tire.

So to calculate the actual overall height of the tire is you take 265 and multiply it by .75. This gives you a sidewall height of 198.75 millimeters.

Now take the 198.75 and divide that by 25. This will give you the sidewall height is inches.

198.75 divided by 25 = 7.95. The number 7.95 is the sidewall height in inches.

Now take the 7.95 and multiply it by 2. 7.95 muliplied by 2 equals 15.9.

Now take 15.9 and add the size of the rim which is 16. 15.9+16=31.9

So the overall height of the tire is 31.9 inches.

If ya do the same to the 265/70R17 tire. The overall height of the tire is 30.84 inches.

So you actually loose 1 inch of tire height with the 265/70R17's than the 265/75R16's.

sdtahoe · November 3, 2003

The 265-75-16 and the 265-70-17 are the same size of tire (31.8" outside diameter) with the only difference being the size of hole in the center for the rim.

The 17's will not gain you any ground clearance, the only way you can gain clearance is with a taller tire.

But the 17's can really change the look of a vehicle and the factory 17's can be purchased fairly cheap. (I paid $250 for a set of 4 Escalade wheels.)

new wheels

Mine do fill the wheel wells a little more as I had 245-75-16's on before.

Elwood 2000 · November 3, 2003

What if the tires are brand new or have 50,000 miles on them??

JUST KIDDING!!!

Red 'rado · November 3, 2003

If you want to compare the height or width of different size tires I suggest you go to http://www.miata.net/garage/tirecalc.html. This type of calculator is used by all tire shops to help the customer quickly compare tire sizes when plus sizing to larger wheels.

According to this calculator it says the 265/70/17 and the 265/75/16 have the same height. No need for complicated calculations. Hope this helps.

RidesGuy · November 3, 2003

Side by side real life no calculators comparsions show the truth. The 17" wheels/tires are slightly taller than the stock 16" Z71 265's. They are in my garage for my comparsion. The tire pressures are nearly the same also.

ebod · November 3, 2003

Are the factory 17" wheels any wider than the factory 16" wheels? If so, then they may be easier to mount bigger tires on down the road (e.g., go to 285/70/17 instead of the typical 285/75/16 (which, IMO, makes the sidewalls look too convex on stock 16" rims)).

sdtahoe · November 4, 2003

The Escalade rims are a 17" x 7.5" so they are a little wider, not sure what the other 17's widths are. Also there are always variations in the exact height between different manufacturers of tires and also between LT series and P series tires.