Tyre query (50 versus 55)

[stu99]

My car (SLK 200) is curently running a 225/55/16R tyre size on the front.

In considering the preferred or compatible rear tyre size option - which is best between a 205/50/16R and a 205/55/16R and what is the difference?

Thanks in anticipation of response.

 

[Blobcat]

Put the figures into this site http://www.tyresave.co.uk/tyresize.html you can then compare the sizes.
From your figures there is quite a difference in circumference which will affect speedo readings and possible bodywork issues.

 

[stu99]

Thanks for speedy response - link gives useful tabulations and info about the difference but as I don't know the size of the original tyres on the rear (i.e. 50 or 55), I'm not clear on what to order.

 

[Blobcat]

I would check first to avoid an expensive mistake.
You can also click on the advice section (top left) from the attached http://www.mytyres.co.uk/start.html then select MB & SLK

 

[Rory]

My car (SLK 200) is curently running a 225/55/16R tyre size on the front.

In considering the preferred or compatible rear tyre size option - which is best between a 205/50/16R and a 205/55/16R and what is the difference?

Thanks in anticipation of response.

It seems odd to me that your front tyres would be wider than the rears.

Quite a few MB's have a staggered set up, including my C270 Avantgarde. That has 205/55R16 on the front and 225/50R16 on the rear. I *think* the front wheels are 7J and the rears 8J.
The critical thing (apart from making sure the tyres will fit the wheels and not foul the arches etc) is that the front and rear need to be near as dammit the same rolling circumference, otherwise cruise won't work and there could be other issues.
This site is good one for size comparision: http://www.miata.net/garage/tirecalc.html

Does the VIN number decoder info tell you the original tyre size?

 

[Blobcat]

Does the VIN number decoder info tell you the original tyre size?

No, but it does detail the wheels fitted and make of tyres

 

[Rory]

No, but it does detail the wheels fitted and make of tyres

Yes, I just checked and found that.

Maybe a dealer would have more detailed info.

 

[clive williams]

My car (SLK 200) is curently running a 225/55/16R tyre size on the front.

In considering the preferred or compatible rear tyre size option - which is best between a 205/50/16R and a 205/55/16R and what is the difference?

Thanks in anticipation of response.

Stu, what does the handbook say about your standard tyres? I would have expected 205/55/16s as standard. Your car is not particularly powerful or heavy and doesn't need 225s of any sort - it will be slower. If you've got 225s on the front then I would fit them on the back and fit standard 205s on the front. The gearing will be slightly higher (~3.5%) but will provide some of the standard balance front/rear and there will be less likelihood of front tyres damaging the wheel arches.

Clive

500E
E320CDIT210

 

[stu99]

It seems odd to me that your front tyres would be wider than the rears.

Sorry - you're right - my mistake - the fronts are 205 and the rears should be 225

 

[clive williams]

Sorry - you're right - my mistake - the fronts are 205 and the rears should be 225

Stu, the fronts should be the same o/a diameter as the rears. Therefore, the rears should be 225/50/16. As said previously, the larger aspect ratio on the rear won't cause too much of a problem except when you have a puncture on the rear - the diff won't like it.

Clive

500E
E320CDIT210

 

[stu99]

Clive -thanks for your input,

So if I'm currently running 205/55/16R on the front then I should be running 225/55/16R on the rear?

I've just had a quick look at the owners handbook. If I understand it correctly, it indicates standard versus mixed tyres. Under the standard option there is no breakdown for front versus rear, only summer versus winter. Under the mixed option, the summer recommendations are 205/55/R16 91V (front) and 225/50/R16 92V (rear) - this is slightly at variance with what you are suggesting

 

[television]

Clive -thanks for your input,

So if I'm currently running 205/55/16R on the front then I should be running 225/55/16R on the rear?

I've just had a quick look at the owners handbook. If I understand it correctly, it indicates standard versus mixed tyres. Under the standard option there is no breakdown for front versus rear, only summer versus winter. Under the mixed option, the summer recommendations are 205/55/R16 91V (front) and 225/50/R16 92V (rear) - this is slightly at variance with what you are suggesting

No its not Stu99 that's exactly what Clive said they should be. you need 50's on the rear,not 55's

Malcolm

 

[clive williams]

Clive -thanks for your input,

So if I'm currently running 205/55/16R on the front then I should be running 225/55/16R on the rear?

I've just had a quick look at the owners handbook. If I understand it correctly, it indicates standard versus mixed tyres. Under the standard option there is no breakdown for front versus rear, only summer versus winter. Under the mixed option, the summer recommendations are 205/55/R16 91V (front) and 225/50/R16 92V (rear) - this is slightly at variance with what you are suggesting

Stu, I only suggested using the 225/55s on the rear if you already had them, which is what I understood from your thread. The 225/50s are the correct fitment for the rear only, which is what I explained in the second response.

Sorry for any confusion.

Clive

500E
E320CDIT210

 

[Rory]

Under the mixed option, the summer recommendations are 205/55/R16 91V (front) and 225/50/R16 92V (rear)

..and that's exactly the sizes that are factory fitted on my car.