I stopped at Discount Tire today to check out prices on tires and wheels. I would like to do some 18's, perhaps 20s but I am leaning more towards 18's. I am looking at the KMC XD Diesel and either Nitto Terra Grapplers or M/T ATZ's. I'm probably going to do the Terra Grapplers though. Anyway, I want size 325/65/18. The wheels are 18x9. The guy says they won't fit my 3500 without rubbing. I have 35" MTZ's on the stock alloys right now, and they are far from rubbing anything anywhere. I know that backspacing/offset plays a part, but I have seen all kinds of trucks running this same wheel in 18 and 20 inch sizes on 35" tires. I like the wheel and have pretty much narrowed my decision down to them. Any suggestions?

 

If the wheels have between 5.5" and 6" of backspacing you should be fine with a level kit and will get some rub on the plastic fender liner with no lift. Backspacing is key. Try to get as close to 6" as possible, and keep wheel width to a minimum (I recommend 9" wide maximum).

 

Well a leveling kit on my truck is not necessary, it's a 3500 and already level. I think the 3500 4x4's are level from the factory aren't they?
Also, I still don't fully understand the difference between backspacing and offset.

 

No, they're not level. The rear is a couple inches higher than the front.

Offset is the distance from the centerline of the wheel to the mounting surface. Backspacing is the distance from the inside lip of the wheel to the mounting surface.

 

Ahh okay, I see now. Thanks a bunch! So I can run 35's on 18's provided the backspacing is 5.5 to 6....

The guy was also saying that the tires would look funny being 12.50 wide mounted on a 9 inch rim, but I had 305/55/20's on 20x9" wheels and they looked just fine, perfect IMO.

How wide are the factory alloys? The 35's I have on them now look fine, and I don't see going an inch bigger making that huge of a difference.

 

I think the factory alloys are 8" wide.

And don't listen to that goober at the tire shop. A 12.50" wide tire looks great on the factory alloys.

 

Yeah, that's true. I told him I already had 35's on the factory alloys and they looked great, and did not rub either. I also told him I hang out with and know of all kinds of guys that have put 35's on 18" and 20" wheels on leveled trucks with no issues. He said something like "I'm just going by what the computer/manufacturer says" or something of that nature. I said "I bet you believe everything the media and the government says too, eh?" and he kind of gave me an evil snicker.

Anyway, for the combo I wanted he gave me a price of 2300 OTD. I know I can do better, but I was going to do the 0% 12 months financing through them instead of paying a buttload of cash all at once. Not sure what I'll do now, I'm not hurting for rubber but I'm probably a couple/few months away.

 

FWIW, I'm running a 13.50" on a 9" rim, and I don't think it looks funny...





--Eric

 

I don't think the XD Diesels are going to work in either of the sizes that you are looking at. The 18's are 9" wide, have a 0mm offset, and 5" backspacing. The 20's are 10" wide, have a -24mm offset, and 4.5" backspacing. Both would rub bad with only a leveling kit. You may need to find another wheel series unless there is a size not listed.

 

Yeah that's what I am looking at, a lot of places online weren't listing backspacing. I know I want black with a chrome/silver lip, so my options are pretty narrow. I've always like the KMC backseats in black, but they're always on a million year backorder.

 

Let's see if I can help you find a couple wheels that match what you're looking for and have the correct offset/backspacing. From there you can search through lots of different websites and find some wheels that are similiar in regards to specs. If you can't find the offset/backspacing on a website, sometimes the manufacturers site has the specs. Here are three that would look good IMO......

Gear Alloy Injectors- 18x9, 25mm offset, 6" backspacing
http://www.tiresdelivered.com/712MB-8908125.htm

Gear Alloy Double Pump- 18x9, 25mm offset, 6" backspacing
http://www.tiresdelivered.com/713MB-8908125.htm

Helo 835- 18x9, 15mm offset, 5.59" backspacing
http://www.tiresdelivered.com/HE83589080318.htm

 

Man you rock, thanks, you don't have to go out of your way like that!

 

No problem. There's not much going on at work today and I need something to do. Besides, I would hate to see someone buy a set of wheels and then regret the decision because the backspacing/offset is all wrong for what they are trying to accomplish. I was suckered into buying 18x9 wheels with 4.5" backspacing and I ended up having to install a lift to clear my tire/wheel combo and at the time I wasn't planning on it. Backspacing is key when you are wanting to fit 35's with a leveling kit or no lift at all. The best advice I can give you is to pay attention to the tire/wheel advice that guys like ptgarcia, chipmonk, thurenfab, and others give you on here. Don't listen to the guys at tire stores. Most of the time they'll tell you that 35's won't fit or that you need 4.5" backspacing to clear your spindles (yes I said spindles; I've heard that before too).

 

The xd diesel will not fit, ill tell you what happened to me. I bought the diesel's and 35" nitto mud grappler, they in stalled them after telling me they would fit no prob. as soon as a started to drive away i heard this nasty noise. They tire's had been rubbing on my fenders, tput it in reverse and cussed out the pimple faced tire boy. Anyway got all my money back and now waiting for the xd spy's. I called kmc and had the guy there help me out. Just food for thought, Chad!

 

I have 20x9 gear alloy injectors with 5.4 bs i am running 35/12.5 pro comps and they do not rub anywhere with 2 in level kit