What are the advantages and disadvantages to putting on larger tires. My Hypertech will accomodate them but not sure whether to do it or not. I guess that 285 is about as big as you should go on a stock truck. Can't help wonder why GM went with the 245.





Snakebite

I would like larger tires too but, I am about as tall as I can be without raising my 5th wheel. It sits a little butt down now. Seems most get better solo mileage with bigger tires on the highway at least. It will cut into your towing grunt since you are effectively lowering the gear ratio. I think it's about a 6% diameter diffference with the 285's.

245's were put on due to roll over concerns, GM does NOT support any Tire sizes other than 245's for the Duramax , some one made mention that the 3500 series has 265's , i have not confirmed this...YET.

Yes, My brother has a new 3500 Gaser. It came with 265's.


I put 285's on last friday. Looks so much better than the stock 245's.


I went with Goodyear ATS's because I have a friend at goodyear.


couldnt beat the price.

Procomp Tires are on sale again. They are offering the buy 3 get one free until the end of the month.


I also don't know if I should go with the 285/75/16 or the 265/75/16 on the stock wheel as I also pull a 5th wheel. I, like most people think the 245's are way to small.


BigdaddyG, are you running 285's?

Nope running the 245's. I have my bars cranked to level the truck out but haven't gotten bigger tires yet. If I cahnge it would only be up to the 265's because I think GM will think 1 upsize is OK and I don't want to lose much towing grunt. I wish this truck had a six speed tranny for my solo driving, I like to drive a bit fast but I keep it sensible so the RPM's aren't so high. The height of my 5th wheel dictates that I can't raise the truck without raising the 5er. Could flip the trailers axles for around $400.00 I guess but heck everything works now.

Get some Juice and then the 285's won't hurt your towing....http://www.dieselplace.com/forum/smileys/Big Smile.gif

Snakebite,


I went to Michelin 265's because they have a 400# higher rating, and I like the extra margin for towing heavy like I do. I can't tell much, if any difference in power, and I tow in the Colorado Rockies. I am completely stock except for the tires and wheels.


I also can't tell much difference in rpm vs. mph. with 245's I was 1850 rpm at 65 mph, now I'm about 2,000 rpm at 65 mph. I drove a 2004 the other day, and it was 2,000 rpm at 65 with the 245's.


As far as GM putting 245's on because of rollover issues, I wonder about that, because they put 265's on 1/2 ton Z-71's.


Regards,


Bill

I put 285 BFG-KO's on my 2500.When I towed our 5er with it there was a difference in power,& at the time I had the Hot Juice in it.At 2000rpm I was doing about 71mph,& if you were doing 65 it felt like you were lugging it.2000-2200rpm seems to be where mine is happy.

I put 235/85's on the 3500 I tow with now & they're about the same as 265's in dia.So now my sweet spot is around 68mph.

I bought some 285s and didn't like the ride. It also cut my driving around town mileage from around 17mpg to 14mpg. Felt like I was pulling something the whole time. I took them back and got 265s and really like them alot. My mileage is back up and I like the ride better. I pull a 5er also and they didn't seem to impact my towing at all. I am going to have to do something with the 5er though. It is lower in the backend. I am going to try to raise the stinger and if that is not enough I will have to have the axles flipped.

[QUOTE=Braz]I bought some 285s and didn't like the ride. It also cut my driving around town mileage from around 17mpg to 14mpg. QUOTE]





Remember, if you are using the computer to figure mileage you must add 10% since the tires are larger. The cc figures mileage off the odometer and the odometer is calibrated off the 245s.

I found a neat tire size calculator that shows the results of changeing tire sizes.


http://www.miata.net/garage/tirecalc.html





Snakebite

I believe the stock wheels on a 2500HD are 6.5 inches wide and the 245's are at the end of the fit range. 265's and 285's should have a 8-10 inch wide wheel or something close to that. tis probably a tad bit unsafe to run to wide of a tire for the wheel and tow near max loads. But it also looke like a tire dealer wouldn't mount a tire that could cause potential problems or they could be liable for damages if sued. Maybe????? Who knows!!!! Have a nice day.http://dieselplace.com/forum/smileys/Big%20Smile.gif

Although the charts say a 7" wheel is needed, COSCO mounts the 265 Michelin LTX/MS on our OEM 6.5" rims and swears it is compliance with the manufacturer. They are very strict about staying in-spec. Another member on here verified this is OK with Michelin.


COSCO has a $80 sale on Michelins going on now.