What tire size are you running? Thinking about going to 33" tires....

[Big Red Suburban]

Here's the situation... My 95 suburban has the stock gray steel wheels and 245/75-16 tires on it. The tires have 10,000 miles or so left and the wheels are just plain ugly. I am going to upgrade to the new style polished aluminum wheels that they offer from the factory (trying to get a set used) and replace the tires as well. I was thinking somewhere between a 265/75-16 and a 33x12.5-16?

The reason for the tire size change is the fact that the suburban has 4.10 gears and currently I don't pull anything other that my jetski. I was hoping to increase the mpg a little bit from a consistant 15 mpg.

Would this much of a tire change (possibly to 33") tires make the truck feel even more like a dog? I plan to do the exhaust, chip, cooling mods, etc... but it may take me a year to get it all done.

Opinions?

[slagona]

I was considering the same swap as you are considering. I had the ugly steel wheels. A take-off set of GM YPO's can be pricey - over $600 with shipping on ebay from reputable sellers.

I decided to go with the stock Hummer H2 alloy wheels. They are 17" x 8" with GM's standard 8 lug hole pattern. I put BF Goodrich Long Trail TA 265/70/17's on them. These are 31.7 inches tall. The stock tires (245/75/16's) are 30.6 inches tall. I have a 3:42 diff ratio and I am really happy with these tires. The best part is that they are passenger rated 35psi tires yet still have a combined GVWR of about 9600 lbs. The ride is really smooth. You can get hummer H2 take-off rims for under $300 on ebay. I think they look a lot nicer than the GM YPO's. For pictures, you can look at:

http://community.webshots.com/user/swlagona

The hummer rims weigh 12 pounds less than the stock steel rims, which is another nice feature.

You could put on 285/70/17's and have a 32.8" tire or the 315/70/17's and have a 34.5" tire. The 315's are the stock Hummer H2 size and are available as complete take-off's on ebay. Would be a good way to get a complete set. When I had mine installed, the installer claimed the 315's would fit on the classic body style GM trucks with just a slight modification to the front - raise it a bit via the torsion bars. He installed several sets on GM vehicles using this method and had no clearance problems.

I'd highly recommend the hummer rims!

--Scott

[Chad Mac]

I previously had BFG Muds 33/12.50/16.5's and have been riding on BFG All Terrains 35/12.50/16.5's for the last 9 months.

I got the truck with the 33's on it so I really couldn't say if there was a difference between the stocks as far as performance loss goes. I can tell you that I didn't really feel too much of a difference by going from 33's to 35's. My gas mileage did increase from an average 15 mpg to 16 mpg with the increase to the 35's.

My truck is really bone stock except for 7" lift in front and 5" in back. My rims are Welds 9.75 X 16.5 and my gears are 4.10 on a K3500. The BFG All Terrains are very smooth and quiet.

I believe that you would have to lift it more than 3 inches if you wanted to go with 33's. The fender wells in our trucks are not meant to house the larger tires with out the lift. I remember that my 33's used to rub every time I would turn into a raised driveway when I had my lift turned down to 5" in front.

By the way, those Hummer take-offs do look pretty sweet on the burb!

Good luck!

Chad Mac

[C.K. Piquup]

Unless you want to spend $1,500 plus labor for a lift-kit to save on fuel,the biggest tire you can run would be 285/75x16 on those factory rims you had in mind.Go to 8"rims and clearance is tight even after bumper trimming.For these tires,you will need to tweek the torsion bars up a bit.

[Phil Holmen]

I am currently running LT285/75R16 on the stock aluminum rims that I too switched to from the stock steel wheels. I have 3.73 gears and with the oversized tire I switched out my vssb to one from a truck with 3.42 and my speedo is within 1mph according to a gps. I tow a 25' 5th wheel with a truck and trailer combined weight of 13,500lbs... tows great just have to watch the egt's on the uphill on warmer days...

[Big Red Suburban]

Wow, I didn't have any idea I could use those rims. I do like the look of them, and they are so cheap...

slagona, did you have to modify the center caps to get them to fit on your axles?

I would love to make the jump to the Hummer stock tire size (that would be a reduction in rpms by about 13%...a reduction of 10% would be like switching to 3.73 gears), however I don't feel like spending the extra money for a lift kit right now. It would definately look nice though!

Where is the tire rubbing a concern? Does it hit the outside of the fender? The wheel well? The bumper? Anyone have any pics of some larger tires on a suburban?

[slagona]

The Hummer center caps fit on most GM vehicles without any modifications. From what I was told, they fit without modification on all GM front "axles". The rear axles of some vehicles might require some modification of the center caps. I was never able to get a "for sure" answer as to which vehicles require modifications - but my interpretation is that the HD one ton full floating axle might be the one. For my 1/2 ton semi floating rear axle, they fit without modification. I was also told that if anything was required, it would be the cutting or removing of a few tabs or the wire ring on the inside of the center cap. They will fit all GM vehicles if some cutting is done - it is all on the inside and does not show on the outside. Another good thing about the Hummer wheels is the center caps are available on ebay. So playing with a few extras to modify for fit (if necessary) isn't a big deal. Of course, these will not fit duallies.....

I'm not sure where the tires rub - I wasn't brave enough to go any larger, but one of these days I'll measure to see how much clearance I still have.

--Scott

[Chad Mac]

My 33's would rub the back of the fender well on a sharp bumpy turn with the outside of the tire. It was also very close to hitting the front bumper with the outside of the tire when turning the other way. You could get around the rubbing problem a little by cutting a small piece of the corner of the bumper off or trimming your fender flares at the bottom of the back of the fender well. But the fact is that the wheel wells are not perfectly round like a Ford's and will not accept the bigger tires without a lift. NOT worth it (lift costs up to $2K) if you are just looking for more MPG's but my truck looks awesome.

Chad Mac

[richard7]

Hummer H2 wheels are quite a deal but the center caps have to be replaced or modified to fit a 3500 truck.
You either have to cut the original center cap (making a 4" or so hole in the center) and glue an aftermarket chromed center you can buy at a wheel store. You can even just cut the hole you need and paint the part of the axle coming out the same color as the cap (silver) and you're done. Or you have to cut your existing center caps with a lathe to reduce the OD (from around 8.25" to about 8") to fit the wheel. This will make your wheel look completely OEM. tongue.gif

I have bought a set for my Savana and haven't decided yet which way I will go. I have yet to try to cut with a lathe before making a decision.
Then I will be happy to sell the original wheel and tire combination, even if they are quite nice as they are.

On my vehicle, H2 center caps won't even fit the front axle, bearing cap going out by around 3/4" too much.

[Big Red Suburban]

Well, I just bought some Hummer H2 wheels for $150! I am going to pick them up this weekend in Kansas City.

Now to pick out some tires. I'm looking at some Nitto Terra Grappler 265/70-17.

Any opinions on tires in this size?

[richard7]

Most 265/70/17 tires have a load rating of 113 (2535 lbs) except the BFG Rugged Trail T/A which has an "E" load rating (3086 lbs).

The lower rating pressure of those tires make you have a more confortable ride, but you are loosing the load capacity if you need it.

Personnally, I will look at more rubber to the ground with either a 275/65 (Nitto) or 285/60 tire, with a load rating of 115 (2679 lbs) minimum.

[Big Red Suburban]

I finally got some answers on the load ratings of tires. Here goes...There are two load ratings to look for, one is the three digit number which represents a certain weight rating (from a table) in lbs that each tire can safely handle. The other load rating is the letter designation if it has one.

For example, load ratings like "C" "D" or "E" can be found on some tires. These represent the sidewall stiffness and ability to handle more air pressure (50psi, 65psi, and 80psi) respectively. In the old days instead of C,D, or E they called them plies. A "C" would be equivalent to 6 plies, "D" is 8 plies, and "E" is 10 plies. However this is not to be confused with the number of tread plies and sidewall plies used in todays tires. The rubber compound is so much better now that to get an equivalent 6 ply, 8 ply, or 10 ply, that many plies are not physically required so the tire manufacturers rate them with load ratings on a letter scale.

My suburban came stock with "E" rated tires so I would like to get news ones with the same rating. In this tire size, it limited my choices, but I eventually found the BFG Rugged Trail T/A LT265/70/17E (for a decent price too).

[cruzer]

You also have to watch out, not a "E" rated tires
have the same max lbs. Ive seen them range from approx 2600-3450lbs.

[Big Red Suburban]

That's true. You really need to pay attention to both the load rating in lbs and the load rating "letter designation".

The tires I'm looking at are rated for ~3080 lbs. So no issues there.

[fogg65td]

On my k 3500 im running 305/70r16 on 16x8 inch wheels. Had to slightly trim the bumper and fender flare as well a crank up the torsion bars. I only have slight rubbing in extreme situations but never in daily driving. Have no clearance probs in the back. Prior to this i had 285/75r 16 on stock wheels and had no rubbing. Just my 2 cents