Quick help needed! Is it safe to put 2 different sized tires on the rear of your M3? - Page 2 - TriStateTuners.com :: Home of Tristate Auto Enthusiast

EklipzGSXkid · 11-19-2010, 11:17 AM

I don't even think it's completly about running a different tire. It's the point that the owner has an m3 but cannot afford to keep up with it, Regardless if he can in a few weeks, He cannot buy two same size/matching tires? Sell the car, Buy something cheaper and eliminate the problem. If you cannot afford for $500 for two good tires, Then you probably shoulden't have the car, Because when something major goes wrong, You will be in a bit more trouble then you are now with not being able to afford one tire.

jpalamar · 11-19-2010, 11:21 AM

Quote:

Originally Posted by EklipzGSXkid

I don't even think it's completly about running a different tire. It's the point that the owner has an m3 but cannot afford to keep up with it, Regardless if he can in a few weeks, He cannot buy two same size/matching tires? Sell the car, Buy something cheaper and eliminate the problem. If you cannot afford for $500 for two good tires, Then you probably shoulden't have the car, Because when something major goes wrong, You will be in a bit more trouble then you are now with not being able to afford one tire.

This, and the simple fact he was able to track his car a few weeks ago makes it funny. If he would of lost his job or something it would be different.. but this is just silly.

russiankid · 11-19-2010, 11:33 AM

If you want to burn up the LSD, sure.

01 Trans-Am WS6 · 11-19-2010, 01:39 PM

Quote:

Originally Posted by EklipzGSXkid

I don't even think it's completly about running a different tire. It's the point that the owner has an m3 but cannot afford to keep up with it, Regardless if he can in a few weeks, He cannot buy two same size/matching tires? Sell the car, Buy something cheaper and eliminate the problem. If you cannot afford for $500 for two good tires, Then you probably shoulden't have the car, Because when something major goes wrong, You will be in a bit more trouble then you are now with not being able to afford one tire.

Well actually the reason I currently have no extra money is because I just used all of it to fix my car from it being broken at the track. I am inbetween jobs right now and currently going through the layover before I get my first check from my new job. I can afford the upkeep on the car, I just saw a potential good deal and asked if it would work, it wouldent, so I didnt get them. Actually just about to order 2 matching Bridgestone Potenzas.

Quote:

Originally Posted by jpalamar

This, and the simple fact he was able to track his car a few weeks ago makes it funny. If he would of lost his job or something it would be different.. but this is just silly.

See above post.

jjm4life · 11-19-2010, 02:41 PM

Quote:

Originally Posted by 420sx

You guys are a bunch of pussies. Lol. Its not gonna DESTROY the car at all.

When I first got my wheels/tires for my 240, I got two new fronts, and two used rears. Somehow my buddy mounted 3 225/40/18's and one 255/40/18. I drove with 1 225 and 1 255 on the back for about 2 months. If youre only looking to do it for a few weeks, and the difference is only 10mm... Do it. Its not like youre running a welded dif...

m3>your late 80s crapbox

it will make a difference.

OP- happy you made the right choice here.

420sx · 11-19-2010, 02:43 PM

Quote:

Originally Posted by jjm4life

m3>your late 80s crapbox

it will make a difference.

OP- happy you made the right choice here.

My late 80's crapbox was made in '98.

2001teg · 11-19-2010, 03:09 PM

You WILL NOT burn up the LSD from different width tires. Different width will only affect cornering. Different profiles are what cause the biggest problems. With different profiles each wheel spins at a different speed. Therefore the car "thinks" one wheel has no traction. Therefore engaging the LSD. Same idea as replacing all 4 wheels at once on a AWD vehicle.

420sx · 11-19-2010, 03:32 PM

Quote:

Originally Posted by 2001teg

You WILL NOT burn up the LSD from different width tires. Different width will only affect cornering. Different profiles are what cause the biggest problems. With different profiles each wheel spins at a different speed. Therefore the car "thinks" one wheel has no traction. Therefore engaging the LSD. Same idea as replacing all 4 wheels at once on a AWD vehicle.

While I do agree with you, I should point out that by changing the width of the tire while keeping the same series sidewall, he is still changing the height of the tire, albeit slightly.

275/35/19 would be a 96.25mm sidewall.
285/35/19 would be a 99.75mm sidewall.

We're talking about a difference of less than half a centimeter.

i_ride_fieroGT · 11-19-2010, 06:44 PM

Quote:

Originally Posted by ThePrimerSuspect

Will fail inspection and most likely have issues with abs and traction control since the wheels will be moving at different speeds.

X2.. not worth it just to have tires. It wil fail inspection and could quite possabley screw up your speedometer as well.

jpalamar · 11-19-2010, 07:44 PM

I doubt the speedo sensor is in the rear.

jjm4life · 11-19-2010, 08:07 PM

Quote:

Originally Posted by 420sx

My late 80's crapbox was made in '98.

fair enough, my bad. at least its not a fiero

ho1ywars · 11-20-2010, 01:06 AM

its a dumb idea to put two different sized tires on any car that uses a clutch type differential. even if off by less then a centimeter the one tire will spin slower then the other, cause the clutches to ALWAYS be slipping. they are only designed to slip when turning. So considering most driving is straight, i would say it would decrease the life off the diff. plus bmw uses that "m diff lock **** which works off of wheel speed sensors. so it would prob be like peg legging it when launching or accelerating fast.

JankyS13 · 11-20-2010, 01:14 AM

Quote:

Originally Posted by ThePrimerSuspect

Will fail inspection and most likely have issues with abs and traction control since the wheels will be moving at different speeds.

call me crazy but i dont see width making one tire move faster than the other. now if it was side wall or diameter of the rim along w/ side wall yes his can be an issue. biggest thing i see from this its going to look goofy as all hell. go head ask me how i know.

ho1ywars · 11-20-2010, 01:23 AM

the first and second number are a ratio. the first number is not just the width lol

JankyS13 · 11-20-2010, 01:31 AM

Quote:

Originally Posted by ho1ywars

the first and second number are a ratio. the first number is not just the width lol

you know what i meant not what i scrolled. lol

9 Ball · 11-20-2010, 02:21 AM

Glad you decided to wait. Although one tire is 285/35 and the other 275/35 there is a difference in height. Over the course of a mile one wheel would have made many more rotations than the other. The main concern would be potential damage to the differential. Just park the car for now and wait.

ScoobySTi · 11-20-2010, 10:42 AM

I can't believe it took 23 posts for someone to finally mention the LSD issue for tires of different heights.

ho1ywars · 11-20-2010, 01:01 PM

Quote:

Originally Posted by ScoobySTi

I can't believe it took 23 posts for someone to finally mention the LSD issue for tires of different heights.

welcome to tst. this is why the tech section here sucks haha

01 Trans-Am WS6 · 11-20-2010, 02:59 PM

Quote:

Originally Posted by 9 Ball

Glad you decided to wait. Although one tire is 285/35 and the other 275/35 there is a difference in height. Over the course of a mile one wheel would have made many more rotations than the other. The main concern would be potential damage to the differential. Just park the car for now and wait.

Car parked and waiting for the tires to arrive, wont be til next week however. Glad I asked first before I went ahead and did anything stupid.

9 Ball · 11-20-2010, 11:08 PM

Quote:

Originally Posted by 01 Trans-Am WS6

Car parked and waiting for the tires to arrive, wont be til next week however. Glad I asked first before I went ahead and did anything stupid.

If you're ever in doubt, check out TireRack. There's tons of info, charts on sizing, heights, and will even give you an accurate rotation count over the course of a mile per tire size.

Yeah, I helped a buddy swap diffs from an OEM unit to a more aggressive gear set-up in his E46 M3. Pretty sophisticated part... one part that you definitely want to keep safe.

EDIT: Just saw your thread on M3Forum. "SWC" is the friend I helped. Looks like he answered your question yesterday.

11-20-2010, 02:21 AM	#36
9 Ball Tri-State Post Whore Join Date: Jan 2005 Location: Philadelphia PA Member #70 My Ride: 2003 Mitsubishi Evolution VIII iTrader: (0)	Glad you decided to wait. Although one tire is 285/35 and the other 275/35 there is a difference in height. Over the course of a mile one wheel would have made many more rotations than the other. The main concern would be potential damage to the differential. Just park the car for now and wait. __________________ 150,000 miles and counting.

11-20-2010, 10:42 AM	#37
ScoobySTi Tri-State Aficionado Join Date: Feb 2008 Location: Bensalem, PA Member #6974 My Ride: 2005 Subaru Impreza WRX STi; 92 Mustang LX 5.0 iTrader: (0)	I can't believe it took 23 posts for someone to finally mention the LSD issue for tires of different heights. __________________ 2005 Subaru Impreza WRX STi (Stage 2) -New ACT clutch Installed Thanks Ryan and Drake(Area1320) 1992 Ford Mustang LX 5.0 -The fully primered beast!

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11-19-2010, 11:17 AM	#21
EklipzGSXkid Tri-State Post Whore Join Date: Apr 2007 Location: PA Member #4554 iTrader: (13)	I don't even think it's completly about running a different tire. It's the point that the owner has an m3 but cannot afford to keep up with it, Regardless if he can in a few weeks, He cannot buy two same size/matching tires? Sell the car, Buy something cheaper and eliminate the problem. If you cannot afford for $500 for two good tires, Then you probably shoulden't have the car, Because when something major goes wrong, You will be in a bit more trouble then you are now with not being able to afford one tire.

11-19-2010, 11:33 AM	#23
russiankid Tri-State Post Whore Join Date: May 2008 Location: Lincoln University PA Member #7769 My Ride: 2012 Scion tC iTrader: (0)	If you want to burn up the LSD, sure.

11-19-2010, 03:09 PM	#27
2001teg Tri-State Addict Join Date: Feb 2008 Member #7004 My Ride: 2001 Integra GSR/Type-R iTrader: (0)	You WILL NOT burn up the LSD from different width tires. Different width will only affect cornering. Different profiles are what cause the biggest problems. With different profiles each wheel spins at a different speed. Therefore the car "thinks" one wheel has no traction. Therefore engaging the LSD. Same idea as replacing all 4 wheels at once on a AWD vehicle.

11-19-2010, 07:44 PM	#30
jpalamar TST Ruined My Life! Join Date: May 2009 Location: Orefield, PA Member #13773 My Ride: '14 Mustang GT iTrader: (3)	I doubt the speedo sensor is in the rear.

11-20-2010, 01:06 AM	#32
ho1ywars Tri-State Addict Join Date: Mar 2005 Location: Ewing, New Jersey Member #282 My Ride: S14, EF, 600RR iTrader: (2)	its a dumb idea to put two different sized tires on any car that uses a clutch type differential. even if off by less then a centimeter the one tire will spin slower then the other, cause the clutches to ALWAYS be slipping. they are only designed to slip when turning. So considering most driving is straight, i would say it would decrease the life off the diff. plus bmw uses that "m diff lock **** which works off of wheel speed sensors. so it would prob be like peg legging it when launching or accelerating fast.

11-20-2010, 01:23 AM	#34
ho1ywars Tri-State Addict Join Date: Mar 2005 Location: Ewing, New Jersey Member #282 My Ride: S14, EF, 600RR iTrader: (2)	the first and second number are a ratio. the first number is not just the width lol