Different tire sizes throwing abs codes?

[dumbstixlars]

Hey guys, I'm about to pull the trigger on a new set of wheels and tires for my GT from AM. I decided to call a couple of dealers in my area to see about getting the speedometer re-calibrated since the new rear tires are going to be a little shorter.

The guy in the service department was telling me that since the tire heights are different (255/45/18 front 275/40/18 rear) that it was going to throw an ABS code. In all the threads I read about people swapping tires I haven't see anybody comment on this before. Is there any merit to this or what?

Thanks

 

[lsp408]

I have 255/40/19 and 295/35/20 and no issue

 

[Spd2Stang]

255/40F 285/35 R

no issues.

 

[cobra1718]

He is wrong

 

[SicShelby09]

He is wrong

This ^^

 

[Frank A.]

On a corvette a few years ago, I had a blow out on a rear tire.
I had four winter tires on seperate rims.
I put two of the winter tires on the rear and had the summer tires on the front. The winter tires were substantially smaller than the summer tires.

I not only had abs faults, the car would not go above 55 mph.

The four winter tires were never a problem with all four mounted because they were within the front to back ratio of factory tires.

what I remember from back then is the height ratio front to rear has to be the same (there is a small difference allowed).

If you are swapping four new rims/tires for factory keep the same height ratio front to rear and there should not be an issue.

I have a program that helps you size to within the ratio window. It's on a desktop at home. If I can find it I will pass it on.

 

[five.slow]

yep and unless you are going from your tires to like huge tires the speedo wont be off enough to really matter.

 

[dumbstixlars]

OK, 1010tires calculator says that the rear tires are going to be 26.66" tall (275/40/18), the fronts would be 27.03" tall (255/45/18), and the factory tires are 27.25" tall (235/50/18).

So not real far off, but I don't know what the margin of error for the computer is. I kinda figured he might be bullin' me since he immediately tried to sell me a set of 2013 Boss 19" rims.

 

[MYFSTSVT99L]

255-40-19 on front, 285-35-19 on rear for me, no problems at all

 

[01bluesnake]

Different tire heights can trigger an abs light to come on, but has to be a big enough difference the computer will throw it. I know on big and littles setup 26 & 28 heights, it will trigger the light around 50 mph. A one inch difference may not trigger it, or may cause a code if cruising a lot higher mph.

 

[kevinp]

GM cars had some issues with the 4 channel ABS when you put different diameter front/rear tires on. Not only would you get a light but the ABS would kick in when you were trying to stop the car, found that out for myself at a dragstrip at 125mph.

The rear DRs I have are almost an inch shorter then the stock fronts and I have never had a light while driving or any ABS weirdness at the track with it.

 

[GeorgeInNePa]

On a corvette a few years ago, I had a blow out on a rear tire.
I had four winter tires on seperate rims.
I put two of the winter tires on the rear and had the summer tires on the front. The winter tires were substantially smaller than the summer tires.

I not only had abs faults, the car would not go above 55 mph.

The four winter tires were never a problem with all four mounted because they were within the front to back ratio of factory tires.

what I remember from back then is the height ratio front to rear has to be the same (there is a small difference allowed).

If you are swapping four new rims/tires for factory keep the same height ratio front to rear and there should not be an issue.

I have a program that helps you size to within the ratio window. It's on a desktop at home. If I can find it I will pass it on.

The GM system is different.

 

[lucasjm]

Tire rack told me the same thing..... Will a 285/35/19 on the rear and a 255/35/19 on the front cause any issues? From what I understand the outside diameter will be .5 off.

 

[kona12]

no issues here..

 

[dumbstixlars]

Anybody know if the 255/45's with the 275/40's out back will look funny? Seems like it would since the front tire would be taller. I keep going back and forth between standard or staggered setups and I can't picture that looking right in my head.

 

[kevinp]

Anybody know if the 255/45's with the 275/40's out back will look funny? Seems like it would since the front tire would be taller. I keep going back and forth between standard or staggered setups and I can't picture that looking right in my head.

I have the older GT500 size tires on mine, 255/45/18 and 285/40/18 (9.5" wheels) and even on those the rears look a little shorter than the fronts. On paper they should be the same size but the sidewall looks taller for some reason on the fronts and it makes them appear taller.

I imagine the 275 will look worse, different brands may look OK so its really hard to tell until they are mounted.

 

[dumbstixlars]

I have the older GT500 size tires on mine, 255/45/18 and 285/40/18 (9.5" wheels) and even on those the rears look a little shorter than the fronts. On paper they should be the same size but the sidewall looks taller for some reason on the fronts and it makes them appear taller.

I imagine the 275 will look worse, different brands may look OK so its really hard to tell until they are mounted.

Yeah I want the wider rears, but little details drive me nuts. I'm afraid of getting them and then having the size difference constantly bugging me.

 

[kevinp]

Yeah I want the wider rears, but little details drive me nuts. I'm afraid of getting them and then having the size difference constantly bugging me.

Drives me nuts too. I also use 305/40 555r nittos that are 27.75" tall on the rear on the same style wheel and they look pretty good with the 3/4" taller rear even though the wheel is bit too narrow.

But bolt on the 265/40/18 M/T drag radials on the stock 18" wheels with the stock frobts and it looks pretty silly because they are 1" shorter the 235/50 stock tires.

 

[jack_feenix]

Yeah I want the wider rears, but little details drive me nuts. I'm afraid of getting them and then having the size difference constantly bugging me.

get a tpms sensor they sell em at american muscle and have directions for how to use i got 9.5 in frnts 10 rears with no problems cause of the sync tool.

 

[jack_feenix]

I have the older GT500 size tires on mine, 255/45/18 and 285/40/18 (9.5" wheels) and even on those the rears look a little shorter than the fronts. On paper they should be the same size but the sidewall looks taller for some reason on the fronts and it makes them appear taller.

I imagine the 275 will look worse, different brands may look OK so its really hard to tell until they are mounted.

i got 9.5 frnts and 10 rears the frnts look awesome the rears im a little worried about em rubbing the rear fenders when i decide to slam it a inch or
2. worst case i might have to get the rear fenders rolled out. but it does look good with the stock ride height. i will post up pics soon as im able if u want.