245/75/16 tires to 265/75/16

Me Again wrote:

CapriRacer wrote:
When making a change such as this, you have to be very careful about wheel width.

Stock wheels for LT245/75R16's are typically 6 1/2" wide. An LT265/75R16 needs at least a 7" width.

If you use too narrow a width on a tire, the tread tends to arch and that not only causes wear issues, but the vehicle tends to wander (as reported above!) and be sensitive to cross winds.

Gee Barry, people will ignore your educated tire engineer opinion and just do it because someone else did it! Go figure!

Chris

Agree with this. Had 265's on two different rigs with 6.5" rims. horrible vs 7.5" rims and 265's. I did like latter combo better than stock 245 setup on my GM's.

Also as noted, gear ratio is effectively changed from a 4.10 to a 3.9x, 3.73 to a 3.55, 3.42 to the 3.2x range. THIS MAY effect initial take off depending upon the GR in the trans. If you have a 4 sp 4L80E/TH400, you WILL notice the taller setup. I had a TH400 in my 88. My 96 had an NV4500. 1 or low was not totally unusable, but unusable with stock 245's. With 265's, it made the overall taller, and more Low was more usable on a day in an out basis. Made the rig overall a better driving setup.

I only used LR E's twice. But generally speaking, found the LR D's to me more than ample for my useage and carrying loads. I rarely put 80 lbs in the E's. Usually only had a max of 60-65, or D range pressure only. Not sure if you will find D's today, as easy as you will C's or E rating tires. So unless towing heavy with a 5w, or carrying loads a lot, same some funds if you can find D ratings, take wife out to dinner, probably get more fun from that than the need for E rated tires.

My opinion, yours may vary!

marty

CapriRacer wrote:
When making a change such as this, you have to be very careful about wheel width.

Stock wheels for LT245/75R16's are typically 6 1/2" wide. An LT265/75R16 needs at least a 7" width.

If you use too narrow a width on a tire, the tread tends to arch and that not only causes wear issues, but the vehicle tends to wander (as reported above!) and be sensitive to cross winds.

Gee Barry, people will ignore your educated tire engineer opinion and just do it because someone else did it! Go figure!

Chris

I have run 35" 12.5" tires on the stock size wheels for years- as have thousand and thousands of others. You will be fine!

When making a change such as this, you have to be very careful about wheel width.

Stock wheels for LT245/75R16's are typically 6 1/2" wide. An LT265/75R16 needs at least a 7" width.

If you use too narrow a width on a tire, the tread tends to arch and that not only causes wear issues, but the vehicle tends to wander (as reported above!) and be sensitive to cross winds.

The factory LT265/75R16's on our Old 2001.5. RAM were on 8" wide factory rims. I would not want them on anything narrower.

I have seen quite a few GM's with 265's on the stock 6.5" rims and the sidewalls really roll in.

Chris

I put 265 tires on my GMC 2500HD.

The speedo read about 1 mph fast at 60 mph with the 245 and about 1mph slow with the 265. I left it that way. I think the dealer can correct that in about 10 minutes. The 265 is standard on the 3500HD in 2006.

The 2500 wheels are:
PY2 - 16" x 6.5" Chrome Clad Steel Wheels (5 cutout holes), or
PY0 - 16" x 6.5" Polished Forged Aluminum Wheels.
The 3500 wheels are:
NZ7 - 16" x 7" Chrome Clad Steel Wheels (6 cutout holes).
Aluminum wheels were not available on the 3500 in 2006 or 2007.

The tire specs for the 265 say 7" wide wheels minimum. 245 tire specs say 6.5" wide wheels minimum. Some at dieselplace say the 265 on 6.5" wide wheel are OK, others say the steering can be degraded because the bigger tire has the wrong shape on the narrower wheel.

I bought the 3500 wheels (NZ7) that are 7" wide from a auto recycler. I watched ebay for about 6 months to find them.

With the 265 tires the truck looks better, tows good, and the tires have more weight capacity. The RPM difference is about 80 RPM slower, the same as a 3500. The 265 will raise the rear of the truck 0.6", again the same as a 3500.

I am trading my GMC 2500HD soon for a new Ram 3500 dually. Then I will have way more weight capacity.

Good luck in your decision.

I had 285's on my 2015 Chevy 2500 work truck with no issues. Back to 265's because of tire choice now.

The stock size on a 3500 SRW is the 265 so putting them on a 2500 is no big deal as far as gearing or fender clearance or anything. The 3500 SRW does come with the wider wheels, that's the only issue. If you can get them to work on your wheels then go for it.

My wife wanted them on her 2500. The edge of the tire rubs the plastic splash shield behind the front tires. Power and breaking are unchanged (butt dyno). We planned on putting a 4 inch NTBD lift on it anyway, and the rubbing went away.

I did that with our F250. The speedo read 2% fast with the 245's. With the 265's it's just about perfect comparing the speedo to GPS. Same with my Prius. Went from 215/45 R17's to 215/50 R17's and corrected the speedo. Most manufacturer's calibrate the speedo to read a little fast as it's illegal for it to read slower than actual speed. Better to err on the fast side.