What implications when installing a slightly smaller tire on my Ram truck?

[SaskRebel]

I'm looking to change my LT285-70-17R tires on my truck (need to be replaced as going bald) and putting a slightly smaller tire in its place 265-70-17R. I'd like to switch from AT tires to more of a HT tire as my truck is just for commuting. Going this smaller size really opens up my options by a large amount. I understand that my speedometer will be off about 3% but is there any else I would have to worry about?

I don't know much about trucks so any help would be appreciated.

 

[GTyankee]

I think ..........

as long as the Brakes, including the Calipers, do not touch the rims, i think that you are good to go.

 

[Barr2255]

I'm looking to change my LT285-70-17R tires on my truck (need to be replaced as going bald) and putting a slightly smaller tire in its place 265-70-17R. I'd like to switch from AT tires to more of a HT tire as my truck is just for commuting. Going this smaller size really opens up my options by a large amount. I understand that my speedometer will be off about 3% but is there any else I would have to worry about? View attachment 553226

I don't know much about trucks so any help would be appreciated.

I think ..........

as long as the Brakes, including the Calipers, do not touch the rims, i think that you are good to go.

I'm looking to change my LT285-70-17R tires on my truck (need to be replaced as going bald) and putting a slightly smaller tire in its place 265-70-17R. I'd like to switch from AT tires to more of a HT tire as my truck is just for commuting. Going this smaller size really opens up my options by a large amount. I understand that my speedometer will be off about 3% but is there any else I would have to worry about? View attachment 553226

I don't know much about trucks so any help would be appreciated.

Your good to go, based off what you said your just reducing the width of the tire. You said you want HT anyway as it’s a commuting vehicle. Your absolutely okay with going to that size tire. Just realize that with that tire you won’t want to go to crazy with mud or snow, especially HT type tire. Make sure with your local tire shop that the size your looking at will fit your rim width wise. I believe it will but the tire shop will know for sure. As far as being okay for the truck it 100% is.

 

[SaskRebel]

Thank you for the responses. I just don't want to cause any damage to the truck but I'm probably just over thinking this.

 

[mikeru]

Your good to go, based off what you said your just reducing the width of the tire. You said you want HT anyway as it’s a commuting vehicle. Your absolutely okay with going to that size tire. Just realize that with that tire you won’t want to go to crazy with mud or snow, especially HT type tire. Make sure with your local tire shop that the size your looking at will fit your rim width wise. I believe it will but the tire shop will know for sure. As far as being okay for the truck it 100% is.

He’s actually going down an inch in diameter, not just reducing width.

@SaskRebel you’ll be fine with that size. Your speedometer will be slightly affected as will your odometer. Basically, at 60 you’ll be traveling 58 mph. Not a huge difference but it’s good to know going in.

 

[Barr2255]

He’s actually going down an inch in diameter, not just reducing width.

@SaskRebel you’ll be fine with that size. Your speedometer will be slightly affected as will your odometer. Basically, at 60 you’ll be traveling 58 mph. Not a huge difference but it’s good to know going in.

What am I missing… OP said he’s going from 285-70-17R to 265-70-17R that’s just the width that’s changing… right? 17 is rim size, 70 is height of sidewall… 265 is width of tire…

 

[Marshall]

My truck came with 20 in factory wheels, that I run in summer, the GY wrangers where damn poor in winter as far as turning and stopping where.
After talking to tire shops, I run aftermarket 17 in with high profile ice/snow tires in the winter,
they are close enough to the same height that I don't notice any difference.
I have been running them for for about 4 winters I think, Had to replace the goodyears this spring as they where getting thin, I don't like running on poor tires

You will not hurt the truck at all, your speed may be off a bit, I find the RCMP will write me little notes if my speed is too far off.

 

[star_deceiver]

I'm looking to change my LT285-70-17R tires on my truck (need to be replaced as going bald) and putting a slightly smaller tire in its place 265-70-17R.

what was the stock size that came with the truck when new. 265/70/17 was a stock size on many half tons, so you could just be putting things back to normal.

 

[Dean2]

What am I missing… OP said he’s going from 285-70-17R to 265-70-17R that’s just the width that’s changing… right? 17 is rim size, 70 is height of sidewall… 265 is width of tire…

The width and sidewall are actually a ratio in tires. Wider tire, same sidewall designation, as in 70, ends up being a taller tire. In tires sizes, 285, 265 is the actual width in Millimetres. The sidewall however is not. For example,if the 70 on the sidewall referred to its height in MM, 70MM would only be 2.5", whereas the sidewall is closer to 185 MM in height.

Op - swap the tires if you want, you will be just fine as far as fitment to the pickup is concerned. That said however, a narrower tire does reduce braking, turning, traction on ice or packed snow and straight line traction. That is why sports and racing vehicles have wide tires. You can't get a tire wide enough to provide flotation on a pickup, unless they are HUGE. The reason narrower tires work better in deep snow and mud, is not because they dig down better, it is because there is less resistance to forward motion. You are not pushing as wide a path through the snow or mud. Everywhere else, the narrower tire is not an advantage.

 

[RamDiver]

The reason narrower tires work better in deep snow and mud, is not because they dig down better, it is because there is less resistance to forward motion. You are not pushing as wide a path through the snow or mud. Everywhere else, the narrower tire is not an advantage.

Narrow tires have always proved advantageous in both forward and reverse directions on my truck's whenever snow was involved.

I can't tell you how many times I've pulled out full-sized trucks with fat tires where we were off-roading in mud or snow.

And I was using a small Toyota extended cab with a 4 cylinder engine, equipped with 33/9.5/15 Mud TAs. It rarely got stuck in anything, including sand or gravel.

And, it went backwards very well too.

.

 

[Wild one]

What am I missing… OP said he’s going from 285-70-17R to 265-70-17R that’s just the width that’s changing… right? 17 is rim size, 70 is height of sidewall… 265 is width of tire…

The sidewall height is a percentage number of the width. 70% of 285mm's is taller/more then 70% of 265 mm's.
Thought you were an engineer that knew everything

 

[Dean2]

The sidewall height is a percentage number of the width. 70% of 285mm's is taller/more then 70% of 265 mm's.
Thought you were an engineer that knew everything

I always expressed a 70 sidewall as .7 of the width, a 60 sidewall as .6 etc. but your percentage explanation is probably much easier for most folks to understand. Good explanation.

 

[SaskRebel]

He’s actually going down an inch in diameter, not just reducing width.

@SaskRebel you’ll be fine with that size. Your speedometer will be slightly affected as will your odometer. Basically, at 60 you’ll be traveling 58 mph. Not a huge difference but it’s good to know going in.

What about the TPMS? I would be going from a LT tire to a P tire so the tire pressure of a P rated tire would be much lower. I've read that you can't change the internal computer on ram rebels (no idea if that is true or not)?

 

[SaskRebel]

I always expressed a 70 sidewall as .7 of the width, a 60 sidewall as .6 etc. but your percentage explanation is probably much easier for most folks to understand. Good explanation.

I just learned that like 2 days ago. I thought the sidewall was a fixed amount, didn't know it was a ratio till recently.

 

[SaskRebel]

what was the stock size that came with the truck when new. 265/70/17 was a stock size on many half tons, so you could just be putting things back to normal.

The stock size is LT285-70-17R and that is exactly what my indoor sticker says as well. Spare is LT265-70-17R. My speedometer is definitely out as everytime I drive by any radar, the speed on my speedometer vs the radar speed are never the same. It always shows me going slightly faster then what my truck shows. I suspect that its tuned for 265s any ways but can't prove that.

 

[SaskRebel]

Your good to go, based off what you said your just reducing the width of the tire. You said you want HT anyway as it’s a commuting vehicle. Your absolutely okay with going to that size tire. Just realize that with that tire you won’t want to go to crazy with mud or snow, especially HT type tire. Make sure with your local tire shop that the size your looking at will fit your rim width wise. I believe it will but the tire shop will know for sure. As far as being okay for the truck it 100% is.

I'm looking at an all weather tire. I understand there not the best in the snow/ice but the Nokian ones at least are pretty good. Either way much better then what I'm using now. I only drive about 3500km a year so I'm trying to avoid having 2 sets of tires.

 

[Wild one]

What about the TPMS? I would be going from a LT tire to a P tire so the tire pressure of a P rated tire would be much lower. I've read that you can't change the internal computer on ram rebels (no idea if that is true or not)?

You should be okay on the tpms settings,if not pretty well any dealer can reset the thresholds,or you can do it with AlphaOBD if you want to reset them yourself.

 

[Wild one]

I'm looking at an all weather tire. I understand there not the best in the snow/ice but the Nokian ones at least are pretty good. Either way much better then what I'm using now. I only drive about 3500km a year so I'm trying to avoid having 2 sets of tires.

I'm guessing you're in Saskabush,i grew up in that province and all we ever drove on were All Seasons,and we made out okay,and that was with 2 wheel drive trucks back in the 70's,lol

 

[Dean2]

You should be okay on the tpms settings,if not pretty well any dealer can reset the thresholds,or you can do it with AlphaOBD if you want to reset them yourself.

Unfortunately the dealership can no longer adjust the thresholds. They have been locked out by Stallantis for quite a while. Mine told me in 2021 to use Alpha as that is what they use on their personal vehicles to do it.

 

[Dean2]

I'm looking at an all weather tire. I understand there not the best in the snow/ice but the Nokian ones at least are pretty good. Either way much better then what I'm using now. I only drive about 3500km a year so I'm trying to avoid having 2 sets of tires.

I ran nokian wrg2 followed by wrg4 tires on a lexus GS 430 V8, rear wheel drive. They were an exceptional all weather tire. Great on ice and packed snow, not as good if the snow got over 6 inches but the car didn't have much clearance either. They were also a great summer tire, good and sticky for playing Ricky Road Race in the mountains.