19.5 tires/wheels on a Chev 3500

[omtay77]

Hi All...

New to the forum and 'kind of' new to truck campers, and am hoping those with far more experience than myself can provide some advice.

I have a 2015 Chev 3500HD,long-bed, still stock, gas, 4.10, SRW, running LT265-70R18's OEM.

I'm trying to get the truck set up correctly before I buy my camper of choice (Artic Fox 996). Also, once or twice a year, I plan to hook on a 16' flatbed with an old jeep on it--though most trips by far will be TC only.

In a nutshell, camper alone will put me at the rear (tire/wheel) max, so I'm planning on upgrading to a 19.5 inch wheel. From what I've learned on this forum, as well as others, a 225-70R19.5 is nearly identical (circumference) to my existing OEM's, but the 3970 weight rating still leaves me short of the kind of 'cushion' I'd like to have. The 245-70R19.5 gives me the weight rating I'm looking for, but are about an inch-and-a-half larger in circumference. In measuring my current tire (32"?) and the available room in the wheel wells, it looks like they'll work.

Question: Can someone tell me if the 245-70R19.5 will work on my 3500 without rubbing, etc?

NOTE: I've tried a few times to ask the folks at Rickson, but nobody answers the phone.

Thanks!

tom b.

[markchengr]

Hi, I've been running 19.5's for a few years now. I have a 2007 Classic GMC 3500 D/A SRW crew cab long bed. I have Vision wheels and Hankook DH01 245/70 tires. These have traction treads and do sing on the highway but you get used to it. I'm on my second set of these tires. The first set were replaced at 75,000 miles only due to their age (7 years). It is unsafe to keep tires longer than that on a vehicle that sits for long periods such as mine. They had plenty of tread left but I have had 2 tires on other RV's fail catastrophically due to old age (not pretty). The guys at Les Schwab trimmed a little wheel well liner when I first had them installed so they wouldn't rub. I run 70 front and 60 rear empty and 80 front and 110 rear when carrying my 4,000 lb camper. The speedo is 2 mph low at 60 mph but with the stock tires, it was 2 mph high so I don't worry about it. I think you will find that most factory speedometers vary from true speeds somewhat. They usually shoot for true speed at 50mph and it varies as you move away from that. -Mark.

[wcjeep]

Zero problems. I also do not corner like a race car. GOinG off memory, when empty the front weighs 4500lbs, rear 2500lbs.

[omtay77]

Bill...have you experienced any problems airing your 245's down that low?

[wcjeep]

That explains the rough empty ride.

[omtay77]

...right now, both front and rear @ 80. I'm frankly a little nervous about letting it down below that...I guess I've read too many posts warning about rolling off the rims, etc.

[wcjeep]

What air pressure are you running empty? On my Dodge I run:

Empty - front 60, rear 50

Full - front 85, rear 110

[omtay77]

Here's a few pics...

https://imageshack.com/a/aeg4/1

tom b.

[Grit_dog]

put up a pic!
On the speedo recalibrate, I wouldn't even bother with it. If you're ocd about your speed then just calc the difference for your highway speeds. It will be between 3-5mph anyway. Not enough to worry about and not enough to mess with the electronics of the abs, wheel speed sensors etc.
it also depends what tires the truck is factory calibrated for. If it has 18s then it's probably on the $ for the stock dia but some trucks, namely the last 3 new Fords I've had 11, 13 and '15 models all have/had stock 17" rims with smaller tires than the xlt or Lariat. All have read on the slow side and when I installed larger tires close to the OE diameter of the bigger rims, the speedo was then correct.
Point being, even the mfg don't worry about a few mph off.

[omtay77]

Just a follow-up to my original post....

Last weekend had Vision 81's and Toyo M608Z's in 245-70-19.5 installed on my 2015 Chev 3500 SRW 4x4...no front rubbing whatsoever (a wee bit close, but no problems). The guys at Les Schwab here in Seattle (4th ave S) did a terrific job. They're used to seeing heavy trucks where they're located (industrial area of S Seattle), so had the right balancing equipment along with a wealth of knowledge about truck tires in general.

I've put 50 miles on them so far, and the tendency to grab and follow seams in the pavement is already starting to fade. The balancing seems fine--nothing noticeable up to 70 mph on freeway.

A bit rough riding, but not too bad. Next up is a new set of shocks.

All in all, very pleased so far.

tom b.

[Bigfootchevy]

I have a 2015 Silverado 3500 SRW Crew Cab and I think the new GM's have larger wheel openings, but I don't know that for sure. Its the front wheels that you need to be concerned with.

I would not order 245's until you know for sure the front wheel wells are larger. The last thing you need is your tires rubbing. 225's are the same diameter as your original tires, but if you go to 245's you will need to buy 5 tires and rims as you will need a new spare.

My camper wet is 3700 lbs. I have no problems with my 225's.

Paul

[AH64ID]

I bought 5, but I don't like having a mismatched spare.

[pjay9]

Some chips can do a recalibration whenever you want.

[Bedlam]

OP needs tires with a Load Index of 130 or better for his application.

[omtay77]

Hi Guys...

After reading how durable these tires are, I'll probably just get 4.

...and a couple more questions...

1) I see speedometer calibrators out there starting at around $200, running up to $500+. Since I'll be switching these tires/wheels back and forth a couple times a year, constant trips to the dealership will be a nuisance. Is it possible to do it reliably with one of these aftermarket calibrators?

2) How does the TPMS get reestablished for the upgraded wheels?...or will it be deactivated while the 19.5's are on the rig?

Thanks again guys for all the help

tom b.