tow vehicle tire question

[rentprop1]

well its that time to get some new rubbers, I have a Dodge Ram 1500 and I see the new 09 trucks have the same size rims but the wall height on the tires has increased from a 245 to a 265.....what will this do to ride comfort, and issues while towing ??

I do like the look of more tire in the wheel well and I really don't wanna go with 20 inch rims and the extra cost, I plan to keep the 17 inch rims, but now have an option for tires, will need some by the end of this month.....thanks for the help

pic of the rear well below, there is plenty of room in the front as well ,so no issues while turning and rubbing, I hope :
.

 

[cdreed06]

Re: tow vehicle tire question

You shouldn't have any problems running the larger tires, that is a common thing to do. Your computer will learn the new tires after a little while. They will look good too.

 

[Bifflefan]

Re: tow vehicle tire question

I doubt you will have any issues with the 265's, I had 265's on my old ford and they rubbed just a tad at full turn.

As for the tires, find a tire dealer that is NOT a chain store. Mom and Pop stores are the best. They will have the best advise and the best knowledge of the tires. The chain stores and the high school kids that work at them.... well you know where im going.

I like "Nokein", (i think thats how its spelled) they are Finnish tires, They wear great and have awesome traction. I have 10 ply but you dont need that on a 1/2 ton 6 is good and you will love them.

 

[rspar]

Re: tow vehicle tire question

It slightlychanges the gear ratio and speedometer I don't think the computer will learn that.

 

[Bifflefan]

Re: tow vehicle tire question

It slightlychanges the gear ratio and speedometer I don't think the computer will learn that.

Slightly is right, the roll out is less than 2 inchs difference. the speedo is that far off anyway.

 

[Sea18Horse]

Re: tow vehicle tire question

Your 245 isn't the wall height, it's the width. Sidewall is denoted by the aspect ratio "70" as in 245/70R/17 meaning the sidewall is 70% as tall as the tire is wide. So a 265 series tire may or may not be too wide for your existing wheels. That's something you'll have to check on with the tire shop. It will certainly effect your speedo accuracy. You may be able to get it reprogrammed with the correct tire size depending on the year of the truck. In order to keep the same diameter you would have to go with something like a 265/60 (or 55)R/17. I don't know what the availability of light truck suitable tires in thoses sizes are though.

Cheers......................Todd

 

[Silvertip]

Re: tow vehicle tire question

Speedometers are electric these days and are a lot more accurate than they used to be so 2 inches of circumference will significantly affect the speedometer reading. The ECM also relies on accurate speed input to determine shift points so that would be affected as well. You can change tire size but the ECM must know what the change is and most tire shops can do that (if your model permits that). The real down side is the alteration of the effective final drive ratio. More circumference changes the towing ability in a negative manner.

 

[bruceb58]

Re: tow vehicle tire question

The stock tire is a 265/70R17

If you have a 245/78R17 the newer tire would actually be slight lower than your tire. If you have a 245/75R17, they are very close in height. If your current tire is a 245/70R17 the difference is going to be 14mm *2 overall height difference. A little over an inch overall height of the tire and over 3" in circumferance. It would make your speedometer read 8% low.

You would want to make sure the width of your rim could handle the wider tire.

 

[bruceb58]

Re: tow vehicle tire question

Your computer will learn the new tires after a little while. They will look good too.

No they won't!

 

[HT32BSX115]

Re: tow vehicle tire question

Absolutely right.

If you're going to change the tire size, you'll have to reprogram or replace the VSSB on a GM truck. I don't know what they call it on a Dodge.


Cheers,

Rick

 

[01 cummins]

Re: tow vehicle tire question

The first question is do you have a 4x4 or not? The 265 should not rub either way but you could go bigger and still wont have a problem with rubbing if its 4x4.

I went from 265's to 315's on my ram and its an 01 and it does rub when I turn left but it tows my boat with no problems. If you want a stiffer ride then get a higher load rating tire. If you get an E load range tire then the sidewall will be stiffer but it will give you a rougher ride when the truck is empty .

You will probably get less MPG's with bigger tires because it takes more power to rotate them unless you're on a flat highway.

If you want to fix your speedo then you can get a Hypertech programmer which makes it easy to change but its really not worth it.

 

[rentprop1]

Re: tow vehicle tire question

I re quoted my own post, read this and then read below ......
.

well its that time to get some new rubbers, I have a Dodge Ram 1500 and I see the new 09 trucks have the same size rims but the wall height on the tires has increased from a 245 to a 265.....what will this do to ride comfort, and issues while towing ??

I do like the look of more tire in the wheel well and I really don't wanna go with 20 inch rims and the extra cost, I plan to keep the 17 inch rims, but now have an option for tires, will need some by the end of this month.....thanks for the help

pic of the rear well below, there is plenty of room in the front as well ,so no issues while turning and rubbing, I hope :
.

thanks...I think ?????



you guys got way off topic with the speedo comments, lets for a second pretend I don't care about the speedo, I have a GPS if I need to double check and I actually speed everywhere, so I don't care how fast the needle says....lol

I learned about the wall size from another comment, but

the tires on the truck now are Michelin LTX A/S P245-70R-17
the new 09 Ram 1500's have Goodyear Wrangler SR-A 265-70R-17

and the tire looks a lot bigger in the wheel well.....what I want to do is fill the wheel well and not affect towing......

this is my question ??.....will going with the 265's make the tire look bigger in the wheel well ??
parked side by side to an 09 Dodge that 265 tire looks a lot bigger in there...

 

[rentprop1]

Re: tow vehicle tire question

Your 245 isn't the wall height, it's the width. Sidewall is denoted by the aspect ratio "70" as in 245/70R/17 meaning the sidewall is 70% as tall as the tire is wide.

so by going from a 245 to a 265 this should increase the wall height as well correct, and by how much ??

70 % of 265 is larger than 70 % of 245....

 

[bruceb58]

Re: tow vehicle tire question

The sidewall height will increase 70% of 20mm or 14mm....not much! 8% bigger!

 

[109jb]

Re: tow vehicle tire question

Go for it. It will look better and the difference is noticeable. My GMC truck came with 245 75/16 tires from the factory. My brother has the same truck with 265 75/16 and I will guarantee you that you can SEE the difference in how it fills the wheel well. When I had to buy my first set of tires I went with 285 75/16 tires and they really llook good and fill the wheel well nicely. My truck is a diesel crew cab that I use to tow a lot heavier things than my boat. I didn't want to lose any towing ability. The 245's that were original were load range E, but the 285's I put on a load range D but the weight capacity per tire is actually higher than the original tires. Seems there is overlap in the load ranges and the 285 I got were at the upper of the D range and the originals were kind of lower end of the E range. As for ride, I get amuch better ride from the new 285's than I ever got from the 245's. As far as if they will rub, you can only really tell by putting them on, but the discount tire website lists the larger size tires that should fit. I didn't see where you listed the year of your truck, but I guessed at a 2006 and it shows that it should be able to take up to a 265 70/17 or a 285 60/17 in addition to the stock size. Hope this helps. BTW, on my GMC, going from the 245's to the 285's gives a GPS verified speedo error of 5 mph at 60 mph (ie: speedo says 60, GPS says 65)

 

[APPALOOSA2]

Re: tow vehicle tire question

Your computer will compensate for the tire , the speed sensor is not mounted on the outside of a tire or the inside for that matter. I work at at Dodge dealer.

I have bumped my own tires up to the 265 on a 4x4 dually and yes the speedo is dead on with a GPS.

If you went up to a 35" tire then a reflash would be needed for the computer.

Gear ratio at that small of a change is not noticed.

 

[bruceb58]

Re: tow vehicle tire question

Your computer will compensate for the tire , the speed sensor is not mounted on the outside of a tire or the inside for that matter. I work at at Dodge dealer.

I have bumped my own tires up to the 265 on a 4x4 dually and yes the speedo is dead on with a GPS.

If you went up to a 35" tire then a reflash would be needed for the computer.

Gear ratio at that small of a change is not noticed.

So then tell us...how is the speed calculated then? If you go up in diameter by 8%, which changing from the 245 tire to a 265 tire will do, you will be 8% off in speed and effective gear ratio. it will be like changing you 3.73 gears to a 3.43.

 

[alumi numb]

Re: tow vehicle tire question

I re quoted my own post, read this and then read below ......
.



thanks...I think ?????



you guys got way off topic with the speedo comments, lets for a second pretend I don't care about the speedo, I have a GPS if I need to double check and I actually speed everywhere, so I don't care how fast the needle says....lol

I learned about the wall size from another comment, but

the tires on the truck now are Michelin LTX A/S P245-70R-17
the new 09 Ram 1500's have Goodyear Wrangler SR-A 265-70R-17

and the tire looks a lot bigger in the wheel well.....what I want to do is fill the wheel well and not affect towing......

this is my question ??.....will going with the 265's make the tire look bigger in the wheel well ??
parked side by side to an 09 Dodge that 265 tire looks a lot bigger in there...

04.5 dodge cummins qcab 2 whl drive 325 hp 600 pft 6spd hand shaker.
went from 245's to 265's as you are planning.
very slight drop in ecceleration, speedo 2 mph lower than gps, mpg, handling, braking and wear about the same.
yes they do look better and will stay with 265's, goodrich at's.
the michelins cracked around the bead "very tough to see" and were worthless on anything but dry.
goodrich is owned by michelin but a far better tire in my case.
the computer thing is someone's imagination, 50k on the goodriches now and the speedo is still 2 mph slower.
yes i had the gps, the same one with the 245's, speedo and it were spot on.
my front end sets pretty low and never any rubbing.
i'm kind of skinny and can't slide under the stock air dam.
under the back end can almost stand up "joke".

 

[rentprop1]

Re: tow vehicle tire question

i'm kind of skinny and can't slide under the stock air dam.
under the back end can almost stand up "joke".

10-4 on that I have to jack up the front to change oil

I do plan on putting the front coil spring lifters on one of these days, that 1.5 inch lift makes the front of the truck level

 

[APPALOOSA2]

Re: tow vehicle tire question

So then tell us...how is the speed calculated then? If you go up in diameter by 8%, which changing from the 245 tire to a 265 tire will do, you will be 8% off in speed and effective gear ratio. it will be like changing you 3.73 gears to a 3.43.

I can't see what year truck he has for sure but the speed sensor on most Dodges are on top of the rear diff., some newer models are in the left front wheel bearing. Same sensor as the abs.