2015 E400 Convertible tyres swap??

[peckerpecks]

Hi all, I have an E400 Cabriolet with 19” wheels. The ride is terrible . It has 235/35/R19 on the fronts. I want to add more profile to tyre. Is it ok to change to 235/40/R19 ?

On the rear tyre I have 255/30/R19. Can I change these to 255/35/R19 ?

My tyre guy says ok but he said also check on the forum too. I don’t want to change to 18” alloys as I’ve just had these wheels re cut .

Any advice appreciated.
Thanks all.

 

[SpikyMikey]

The change you are proposing will effect the accuracy of your speedo.
Have a look here:
Alloy Wheel & Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit

 

[peckerpecks]

The change you are proposing will effect the accuracy of your speedo.
Have a look here:
Alloy Wheel & Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit

Hi, thanks for that. A very useful tool. So I suppose my next question is it says it will increase my ride height by 12mm which isn’t a problem for me. And my speedo accuracy will be - 3.5%. So if speedo says 30mph I’m actually doing 28.9mph. Will this cause problems with anything do you think as it’s only a small change?? Thanks for your help.

 

[ALFAitalia]

It will probably just make your speedo more accurate... they all under read from the factory.
It's clearance of the front wheel arch liners on full lock that would be more of a concern to me.

 

[SpikyMikey]

Normally speaking, to increase the side wall you would reduce the wheel size to give near enough the same rolling resistance and, as ALFA says, negate any issues with the tyre touching wheel arches or liners.

 

[Bobby Dazzler]

It will probably be fine.

Catching the arch lip on compression, inner arch or suspension would be the main concern. There is a small possibility that it may upset electronics if it changes the balance of rotational speeds between front and rear axles. Speedo reading and insurance implications should be considered too.

Like I say, it it will probably be OK. Just don’t be too disappointed if you don’t notice a difference in ride comfort though. If you do decide to go ahead, then do take a big dose of placebo to make sure that it was worth changing

 

[DSM10000]

18 inch wheels and tyres will give a better ride but it will never be limousine comfortable

 

[Fastcar155]

Who is the tyre manufacture ?

My car came on Continental 5 p and the ride could have been better.

I changed to Goodyear Assi 5 and the ride was more controlled and comfortable.As others have said it's never going to be a limousine.

Mercedes don't advise changing tyre size.

Your car should have staggered tyre but the wheels are the same size.

I tried increasing the rear tyre size on rear on my car ( but it noticed a difference on handling ) and quickly returned to the correct size.

I really wish I still had mine car.

Hope you sort out the problem

 

[fabes]

As above some tyres ride better.
Read up on here and the web

You could also trial a psi or two reduction before you splash out on the tyres.

Shocks / suspension in good order.....?

I had 18s on my E350 coupe and have 19s on the replacement E400 coupe.

I agree the ride is a little bit harder but the tyres that were on it weren't great and we're worn (I can't recall brand) but as they were quite worn, I swapped the tyres for Hankooks and they make it okay. I run them a psi under book

 

[DSM10000]

Who is the tyre manufacture ?

My car came on Continental 5 p and the ride could have been better.

I changed to Goodyear Assi 5 and the ride was more controlled and comfortable.As others have said it's never going to be a limousine.

Mercedes don't advise changing tyre size.

Your car should have staggered tyre but the wheels are the same size.

I tried increasing the rear tyre size on rear on my car ( but it noticed a difference on handling ) and quickly returned to the correct size.

I really wish I still had mine car.

Hope you sort out the problem

The rear wheels are often wider on a staggered setup