tire choice for HD Duramax

Roofer · November 27, 2002

I have been reading alot of posts on tire size choices. Most go with a 265 on the stock 16x6.5 rim. Some go with 285's and some with 305's on the stock rims. Forum member "Shotgun" runs 305's and claims no problems at all. What would be the choice you would make?

I would go with 305 Xterrains, but am leary about tire wear and the tranny.

TXDMAX · November 28, 2002

Whoops, didn't see you were putting them on stock rims. I wouldn't go w/ anything bigger than a 285/75 on them imo. But I know people that do and them seem to wear great.

SoMnDMAX · November 28, 2002

No bigger than 265's on a 6.5 wheel.

Tire manufacturers put rim size reccomendations in the tire specs for a reason. 285's just aren't safe on a 6.5" wide wheel.

My .02.

Shotgun · November 28, 2002

SoMnDMAX,,,that is pure BS.Sure the manufacturers recommend a wider rim,which has become an issue since the firestone debaucle.So the lawyers and pencil headed execs wanna really cover their buts.My goodyear dealer installs 305's on trucks w/ factory rims here everyday.He says he hasn't had one problem since goodyear started making the MT in a 305 in 1996.This is my second set of 305's .My first set i purchased in '97 and put 44,000 miles on them.I pull an RV that grosses out at about 8,700lbs . The reason the manufacturer doesn't reccomend these tires for 6.5" rims , Because some idiot with 10,000lbs of tools on his truck on a constant basis drives 85 mph 6 days a week back and forth to work and blows a tire and sues ,well they are covered.I went to Kentucky last week with 4,200lbs of Crawfish and drove 75 - 80 the whole way.If you say it's not safe how bout backing that up with some information.

CMNTMXR81 · November 28, 2002

285's here on the stock rim. I wouldn't go bigger than that though because of the crowning issue. But that's just my ol personal perspective. Others have done it with nary a problem.

Roofer · November 28, 2002

Thanks guys. I don't want this to turn into an argument. Everyone has their opinion. I do like facts though. The main reason I am looking at 305's is because Xterrains only come in 305's and bigger, and they are a taller tire.

I realize manufacturers have a rim width for a reason, but I also believe they are just covering their a$$ for the idiot. This happens in alot of things.

Has anyone had a failure with a 285 or 305 on a 16x6.5 rim?

I wonder if the weight of the Dmax has anything to do with the crowning. Or maybe it's because of a certain brand of tire wears more than others. It seems to be a hard question to answer.

Thanks for the replies guys, keep them coming.

SoMnDMAX · November 28, 2002

SoMnDMAX,,,that is pure BS.....

If you say it's not safe how bout backing that up with some information.

Ok. Again, here's my $.02 (also known as an opinion before you rip my head off again...) ???

Tire manufacturers are just that- they are the manufacturers, the designers, etc., which means they have engineers working for them to determine what's the correct application for a certain size tire. Am I a tire engineer? Are you? I know I'm not, and most likey you aren't either. The only info I need to back it up is the specs given in the tire catalogs. Again, as I stated before, they are there for a reason. Obviously you know more about tires than BF Goodrich, Goodyear, Firestone, etc... Maybe you could re-write their catalogs for them.

What you or others do with your/their truck(s) is fine by me. Roofer asked for an opinion, and I gave mine. Take it for what it's worth.

CMNTMXR81 · November 28, 2002

Crowning has to due with the bowing of the center of the tread of a tire when the sidewalls are squeezed together more such as the case on a 6.5" rim vs. a 8' (16x8). Essentially the edges of the tires won't wear as much as the center will.

Deflating tire pressure helps a little and I'm sure more weight to help flatten then will eliminate this, but even with 285's you get a little crowning. Nothing major mind you, but it does happen.

Shaners · November 28, 2002

Around here, alot of tire dealers will not install a tire any bigger than a 265/75 on a 6.5" rim.

You can always go skinnier and taller: For example a 265/75/16 and a 235/85/16 are both approx 31.6" tall. The recommended min. wheel width is 7" and 6" respectively.

hdmax · November 28, 2002

I had been thinking about going with 295/75/16" tires on the stock rims. But after a lot of thought, I have decided to either go with 255/85/16" tires with stock rims, or 295/75/16" tires on 16X8" rims with about a 4 1/4-4 1/2" back spacing.

I think 285/75`s may be too wide for the stock 6.5" wide rims if you haul or tow near the trucks GVWR/GCVWR.

As I stated "I THINK" there for it is my opinion.

Shotgun · November 29, 2002

I enjoy reading everyones opinions ,after all ,thats what this forum is about.But,don't just come on here and post saying the tires I have on my truck are unsafe when it is basicly just here say.As I stated in my earlier post,I am aware of what the manufacturer reccommends,I also ripped the tag off of my matress and I drive over the speed limit too........I will say this,,If you run goodyear 285's on factory rims you will never have any problems....am I an expert? Well that can be argued,,I have common sense and I have run these tires for the past 8yrs on factory rims.I would never jepordize my family's safety.I don't need to read a book to know what tires will fit safely on my factory rims.I do agree with these other guys.CMNTMXR81 & TXDMAX..285's are the way to go........

MarkD · November 29, 2002

One thing that hasn't been covered here...

Aren't there some Allison Tranny issues with bigger tires???

Roofer · November 29, 2002

I have heard of one guy having tranny problems with 285's on his '02. Now he has an '03 HD and he has 265's. I never really asked him about it, but I've heard through others, that is the reason for 265's on his new truck. Most I've seen on the net seem to not have problems. This guy though puts on 70K miles a year. Most on the net don't put on that many miles. I'm not sure what to think of it. My dealer suggested 265's and no bigger, but he may have been thinking about clearance issues.

BTW guys, thanks for not turning this into a brawl. I like to hear the arguments, but nothing personal please.

CMNTMXR81 · November 29, 2002

One thing that hasn't been covered here...

Aren't there some Allison Tranny issues with bigger tires???

Nope.

How are a bigger set of tires gonna hurt a transmission that handles 500+ lbs-ft of input shaft torque?

If an Allison can't handle it, perhaps they should get out of the transmission business.

2001 HD · November 29, 2002

There is a TSB out on the D/A combo about "Non-stock" tires and warranty issues. Dealers will more than likely not warranty any D/A transmission/drivetrain issues with "Non-stock" tires. I don't have the TSB number handy, but do more research before you spend the money.

Shotgun-#4200 of mudbugs sounds good. Stop it, your making me South Louisiana home sick!