BMW front to back tire difference

howyegettinon1

Looking at some new shoes for 523i, when checking the tire size I noticed that the profile on the back tire's is slightly lower than the front.

Front 245/40 R18
Back 245/35 R18

Any reason for this? Should I keep it like this or will I just go with the same size all around?

Thinking of going with these tires great reviews and price looks right, anyone use these before?

http://www.camskill.co.uk/m61b0s323p111417/Vredestein_Tyres_Car_Vredestein_Ultrac_Sessanta_-_245_40_R18_97Y_XL_TL_Fuel_Eff_%3A_E_Wet_Grip%3A_C_NoiseClass%3A_1_Noise%3A_67dB

Trojan

In that price range I'd be looking at the Uniroyal RS3.

My E39 wheels are staggered and the rears are wider with lower profile: 235/45/17 and 255/40/17. Given the profile difference I'm surprised yours are the same width, tyres swapped by a previous owner?

MetzgerMeister

The wheels and tyres at the back are wider for better traction on the driven wheels. It's called a staggered set up and the majority of BMWs and Mercedes cars have it.

Special Circumstances

MetzgerMeister wrote: »

The wheels and tyres at the back are wider for better traction on the driven wheels. It's called a staggered set up and the majority of BMWs and Mercedes cars have it.

But in this case they are they same width, just smaller. Not quite into Delorean territory, but it sounds like previous owner just thought matching tyres were too expensive :pac:

MetzgerMeister

On mine the fronts are 225/45/18 and the rears are 255/35/18.

challengemaster

MetzgerMeister wrote: »

On mine the fronts are 225/45/18 and the rears are 255/35/18.

Yeah, that's the correct stagger. OPs ended up with the wrong profile/size on both....somehow.

You can get away with fitting 225/45 all round if you wanted to. I had a poke around on a couple of manufacturers websites, they have their tolerances listed for the tyres and what rim sizes they'll fit. IIRC 225/45 can go as far as 9J while still complying with manufacturer spec. At 8.5J it's a tiny, not even noticeable stretch.

Gumbo

howyegettinon1 wrote: »

Looking at some new shoes for 523i, when checking the tire size I noticed that the profile on the back tire's is slightly lower than the front.

Front 245/40 R18
Back 245/35 R18

Any reason for this? Should I keep it like this or will I just go with the same size all around?

Thinking of going with these tires great reviews and price looks right, anyone use these before?

http://www.camskill.co.uk/m61b0s323p111417/Vredestein_Tyres_Car_Vredestein_Ultrac_Sessanta_-_245_40_R18_97Y_XL_TL_Fuel_Eff_%3A_E_Wet_Grip%3A_C_NoiseClass%3A_1_Noise%3A_67dB

What wheels have you got?
Some E60 MSport wheels are square fitting all round.

R.O.R

kceire wrote: »

What wheels have you got?
Some E60 MSport wheels are square fitting all round.

Mine should have 245/40/18 all the way round, that's standard fit on the E60 M Sport with the 18" wheels.

I've got 45 profile on front at the moment though as they were free.

allinthehead

R.O.R wrote: »

Mine should have 245/40/18 all the way round, that's standard fit on the E60 M Sport with the 18" wheels.

I've got 45 profile on front at the moment though as they were free.

Ya i've got the 18" msport wheels and they're 245/40/18 front and back

tmg

it should be on the sticker inside the petrol fill thing where it states the tyre pressures no?

Trojan

A lot of E39 saloons are staggered while the tourings are not, could be the same for other models.

bazz26

My old E90 M Sport had a staggered setup:
Front - 225/40/R18
Rear - 255/35/R18

My current F10 has a non staggered setup:
Front/rear - 245/45/R18

The only ones that tend to have a staggered setup from the factory are some of the M Sports or more powerful engined models.

OP the only difference with yours is the profile (height) of the tyre side wall which doesn't appear to be from the factory but rather by the previous owner. Personally I'd go back to the factory setup.

Some good info here:
http://www.wheel-size.com/size/bmw/5-series/2006/#trim-523i-eudm

Voodoomelon

Just to clarify, staggered setups don't have lower profile tyres on the back. Yes it's a lower number, but this is a ratio by comparison to the width. So the tyre wall should actually be the same all round, it's just the numbers make it look like it's smaller.

It can be a pain in the ass getting four matching tyres from the same manufacturer and same model of tyre, 18"+, from the same retailer. Often you have to compromise with X model on the front axle and Y model on the rear axle, from the same manufacturer. At least that's my experience with high end tyres in 18"-20".

howyegettinon1

allinthehead wrote: »

Ya i've got the 18" msport wheels and they're 245/40/18 front and back

yeah that's what I have 18" MV2's, I'll go all round with the same profile so

Gumbo

howyegettinon1 wrote: »

yeah that's what I have 18" MV2's, I'll go all round with the same profile so

That's the way they were designed. A square for all round for the E60 but the E46 MV2's are a staggered set up.