Tyre Size Confusion! R230 SL on 20"

[Balance]

Hi guys! so part of getting my new toy up and running involves changing the tyres along with servicing that you guys helped a lot with.. .... rear tyre have MOT warning (a deep cut on both rear - inside wall ..ouch!) ..... the confusion is with regards to size of them .. so currently front is 255/35/20 and rear is 285/30/20 ... does that ratio seem correct ? I looked at the other thread where the Mercedes-benz wheel fitting chart was ...and as per that pdf, I should have the same profile i.e. 255/30/20 in front and 285/30/20 at rear!

It seems to drive fine with the current tyre size and speedo seems okay too (if compared with navigation system) ... it never bugged me till I actually saw the 35 in front and 30 at back...and now everytime I look at it, it looks raised from front .... sooo what tyre size to go for ?? (next question would be of the brand of tyre obviously! : ) ...




Thanks in advance for the help.

 

[flowrider]

Hi guys! so part of getting my new toy up and running involves changing the tyres along with servicing that you guys helped a lot with.. .... rear tyre have MOT warning (a deep cut on both rear - inside wall ..ouch!) ..... the confusion is with regards to size of them .. so currently front is 255/35/20 and rear is 285/30/20 ... does that ratio seem correct ? I looked at the other thread where the Mercedes-benz wheel fitting chart was ...and as per that pdf, I should have the same profile i.e. 255/30/20 in front and 285/30/20 at rear!

It seems to drive fine with the current tyre size and speedo seems okay too (if compared with navigation system) ... it never bugged me till I actually saw the 35 in front and 30 at back...and now everytime I look at it, it looks raised from front .... sooo what tyre size to go for ?? (next question would be of the brand of tyre obviously! : ) ...


View attachment 100452

Thanks in advance for the help.

Your tyre ratios are for 19" wheels.

 

[AMGeed]

On a 20" wheel set up the recommended tyre sizes on a R230 SL are-:
Fronts 255x30x20 and rears 295x25x20

The rims should be 8.5j and 9.5j

Mercedes SL Class Roadster Alloys (R230) - Alloy Wheels Direct

Purchase some new Mercedes SL Class Roadster alloys. Visit Alloy Wheels Direct for genuine Mercedes & aftermarket alloys to fit your SL Class Roadster R230 - In Stock.

www.alloywheelsdirect.net

 

[Balance]

Thanks guys ....will look its that now.

 

[Abb]

You have managed to get an answer to your question OP within two replies and none giving you life lessons on how much of a mistake you are making running on 20" wheels, from people who have never had them

AMGeed has given you the correct tyre sizes, but I would double check as he is running 16's for comfort on his E63.




(Only kidding, @AMGeed he is indeed the wheel & tyre guru and is spot on)

Can't wait for the tyre thread!

 

[Balance]

You have managed to get an answer to your question OP within two replies and none giving you life lessons on how much of a mistake you are making running on 20" wheels, from people who have never had them

AMGeed has given you the correct tyre sizes, but I would double check as he is running 16's for comfort on his E63.


(Only kidding, @AMGeed he is indeed the wheel & tyre guru and is spot on)

Can't wait for the tyre thread!

well!!!!!!! the way I look at it!!! no matter how painful it looks to us, have you ever managed to convince a female not to wear high pencil heels??? they wear it as it looks good ..............and man o man! SL look good sitting on 20" rims (reminded me of that old Mercedes song

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!

now now @Abb ! just because someone hasn't acted in a porn movie doesn't mean they can't direct a good storyline .... sooo the link @AMGeed shared actually shows the 20" ratios.....so it does answer the question.....however..... bit confusing as in rear it shows both 295/25/20 and 305/25/20 ............. so now me has to see the rear alloy ...its a lot wider (concave), I think its wider than 9.5" ..so if its 10.5" I would get 295/25/20 and if 11" I would get 305/25/20 ...

Now ..the part 2 of question ... anyone tried Lexani LX-Twenty or Falken Azenis FK510 .. they seem to have better grip and noise ratio than the expensive brands ?? can save around £400 replacing all 4s......which I can spend on restoring interior/paint restoration!

 

[Gbrowncls55]

Goodness, 20s on an r230 I went from 17s to 18s and even that ruined the ride

 

[NJSS]

Gbrowncls55

I'm looking to go down from 19" to 17" or 18" to improve the ride

NJSS

 

[flowrider]

19's on my SL are good, I have ABC though which smooths out the ride.

 

[NJSS]

I don't have ABC. In view of the reported failure rate & cost of repairs I'm rather relieved, but accept that anecdotal reports need to be taken with a pinch of salt.

NJSS

 

[W1ghty]

Hi guys! so part of getting my new toy up and running involves changing the tyres along with servicing that you guys helped a lot with.. .... rear tyre have MOT warning (a deep cut on both rear - inside wall ..ouch!) ..... the confusion is with regards to size of them .. so currently front is 255/35/20 and rear is 285/30/20 ... does that ratio seem correct ? I looked at the other thread where the Mercedes-benz wheel fitting chart was ...and as per that pdf, I should have the same profile i.e. 255/30/20 in front and 285/30/20 at rear!

It seems to drive fine with the current tyre size and speedo seems okay too (if compared with navigation system) ... it never bugged me till I actually saw the 35 in front and 30 at back...and now everytime I look at it, it looks raised from front .... sooo what tyre size to go for ?? (next question would be of the brand of tyre obviously! : ) ...


View attachment 100452

Thanks in advance for the help.

Inside the filler cap normally has tyre and wheel sizes

 

[AMGeed]

Now ..the part 2 of question ... anyone tried Lexani LX-Twenty or Falken Azenis FK510 .. they seem to have better grip and noise ratio than the expensive brands ?? can save around £400 replacing all 4s......which I can spend on restoring interior/paint restoration!

Falkens are a decent brand and good value for money.
Had them on my last E55 and they gave good grip in both wet and dry.

No idea on Lexani brand.

 

[Balance]

hi guys..... so was looking for some walk around the issue I am facing ........soooo after the discussion above.......... I ended up buying falken Azenis FK512 - 255/30/20 front and 295/25/20 rear .......and they should fit the rims too ... front is 9.5 and rears 10.5 wide ... (initially it was running 255/35/20 in front and 285/30/20 rear) ....
long story short ........................ went to two tyre places today ...first one tried to put the rear ones on and after 10 minutes gave up saying , it wont fit, tyres are too wide ............ went to another one ... spent hours and hours or beating the crap out of the tyre and actually managed to seat the tyre .. apart from on one corner where bead is not seating properly .......and eventually he gave up as well..........according to him , need a powerful compressor to fill them in ...so recommends going to a truck tyre shop ..which he would do for me tomorrow : ( .................. returning tyres will be huge hassle ..bought it online from tyreleader ... front ones are already on too .... sooo as a backup me thinking if all fails tomorrow I have to get some rear ones that can go with the new front (255/30/20) --- I don't want to buy all 4s again, so have to work with the front ones : ( - what size can go easily ..the tyre guy says 295/30/20 would be easy to put ...25 has too thin sides and hence difficult to stick them on!!! would this ratio be okay ?

obviously! fingers crossed for truck guy to manage it tomorrow!

any tips be useful ...or experience of having to deal with difficult tyre seating and how you resolved it ?? google says falkens is difficult to seat!!!

 

[Abb]

Sorry to hear your woes mate. Your tyre sizes are correct and they should fit, yes they may be difficult but they will fit. Having said that I haven't used Falkens, but used any a 25 profile rear tyre with no issue.
The high pressure inflator bit sounds right though, I remember when one of my fronts couldn't be seated properly (went to a different garage than I normally use) and he said it needed high pressure to enable the tyre to 'pop' and seat correctly.

I recall thinking what a load of carp as I had never heard that one before, but I returned the following day and it had been done (took it away to have done elsewhere for me).

I wouldn't be purchasing new tyres thats for sure, just take them elsewhere, inconvenient it may be, but definitely the cheaper and more sensible solution.

Oh and the 30 rear profile wont be right!

 

[Balance]

Sorry to hear your woes mate. Your tyre sizes are correct and they should fit, yes they may be difficult but they will fit. Having said that I haven't used Falkens, but used any a 25 profile rear tyre with no issue.
The high pressure inflator bit sounds right though, I remember when one of my fronts couldn't be seated properly (went to a different garage than I normally use) and he said it needed high pressure to enable the tyre to 'pop' and seat correctly.

I recall thinking what a load of carp as I had never heard that one before, but I returned the following day and it had been done (took it away to have done elsewhere for me).

I wouldn't be purchasing new tyres thats for sure, just take them elsewhere, inconvenient it may be, but definitely the cheaper and more sensible solution.

Oh and the 30 rear profile wont be right!

Ahh! that's a relief ... on youtube videos they make it look so easy : ) ..so was beginning to believe I got wrong size ....so thanks for the ray of hope!! lets see how it goes tomorrow! : )

 

[Balance]

ah well................so they couldnt mount the tyres on the wheels : ( ....................... went to like 4 shops ................
Was getting frustrated with wasting so much time getting it fixed, sooo ended up buying the 285/30/20 as this is what it was on car when I bought it ..... ( I know wrong tyre size) but it was working ........ so bought them and guy fitted instantly ......... was happily driving home when the car gave the ABS/ESP warning : ( ............and then I realised, that the darn front wheels are now 255/30/20 (as i bought them together with the 295/25/20) ............previously it was working fine with 255/35/20 ................ sooooo now, I have to buy two 255/35/20s tomorrow ........

 

[Balance]

Saying that ........ I have now got 295/25/20 brand new tyres in the house since they couldn't mount them ............and a pair of 255/30/20 (max 10 miles driven) after tomorrow .... bought them online and its a hassle to return ... not sure if they would take them back since the tags and all is removed....+ front ones are actually on it and i drove nearly 10 miles on it already ?? they are FALKEN AZENIS FK510 ...... reviews were good for them .......low noise and A on wet braking.
anyways.......... the reason of post was.....how come car was works fine (speedo and all) + no sensor error with the wrong size of 255/35/20 (F) and 285/30/20 (R) previously (and hopefully after I change the front ones tomorrow)???

 

[Bobby Dazzler]

Saying that ........ I have now got 295/25/20 brand new tyres in the house since they couldn't mount them ............and a pair of 255/30/20 (max 10 miles driven) after tomorrow .... bought them online and its a hassle to return ... not sure if they would take them back since the tags and all is removed....+ front ones are actually on it and i drove nearly 10 miles on it already ?? they are FALKEN AZENIS FK510 ...... reviews were good for them .......low noise and A on wet braking.
anyways.......... the reason of post was.....how come car was works fine (speedo and all) + no sensor error with the wrong size of 255/35/20 (F) and 285/30/20 (R) previously (and hopefully after I change the front ones tomorrow)???

I suspect it’s the difference in rolling radius between the front and rear tyres.

 

[E55BOF]

No, the supplier won't take tyres back if they've been used. You'll find a buyer for them easily enough, though.

This thread is an object lesson on the possible pitfalls of fitting 20" wheels to a car not designed for them. But hey, they look good...

Style before substance.

 

[Abb]

Shame you didn't manage to get it sorted. Goes to show there is a lesson to be learnt with tyre fitting shops/garages. Rest assured, the fault does not lie on your part, if the they couldn't for the tyre onto a rim it is designed to fit (ie both 20") why would they make such profile tyres if it wasn't possible

Plenty of cars driving about with the tyre size on, especially when tuning houses like Brabus get hold of the car!

FWIW, mine are conti contact 6s IIRC, even went up a size to 305/25/20 rears and 255/30/20 on the fronts and have had zero issues with them.

Selling the set you now have spare shouldn't be a problem.