Changing tyre size help with new alloys.

[E350Matty]

Hi all,

Thinking of going ahead and purchase new alloys 19" with a tyre package.

The thing is the new tyres that will be supplied are :

245/40/19 and 275/35/19
Below are the new alloy spec

PCD:	5 × 112
Offset (ET):	40,44
Rim width:	8J and 9J
Centre bore size:	66.6

Mine are currently running on 235/35/19 and rears 255/30/19 , photos attached.

According to the tyre shop they will fit but I will just need longer bolts.

It's not the bolts that worries me it's the width and height of the tyres I'm worried about will it affect my car (apart from the Speedo).

I'm hoping it will run perfect and be more comfortable due to the next height size up.

Thank you for your time and attention.

 

[KennyN]

Front rolling diameter will be + 32mm / 4.75%
Rear rolling diameter will be + 40mm / 6%

Your speedo reading will be out by - 5% compared to your actual speed.

With the new setup there is only -0.52% difference in the front to rear rolling diameter so there should be no issues with the wheel speed sensor readings.

K

 

[SmartAmg]

Will probably get away with it, but the height of the wheel/tyre will be slightly higher, therefore possibly touching the arches. Also the extra width of the tyres might touch the suspension. It's all ifs and buts, really.
Can't you ask them to just supply the correct tyres for your car, if they are from a shop. Don't know why you would need longer bolts though.

 

[DSM10000]

Will probably get away with it, but the height of the wheel/tyre will be slightly higher, therefore possibly touching the arches. Also the extra width of the tyres might touch the suspension. It's all ifs and buts, really.
Can't you ask them to just supply the correct tyres for your car, if they are from a shop. Don't know why you would need longer bolts though.

Is the offset very different to the originals?

 

[SmartAmg]

Will probably get away with it, but the height of the wheel/tyre will be slightly higher, therefore possibly touching the arches. Also the extra width of the tyres might touch the suspension. It's all ifs and buts, re
Can't you ask them to just supply the correct tyres for your car, if they are from a shop. Don't know why you would need longer bolts though.

Is the offset very different to the originals?

Good point, never thought about that.

 

[SpikyMikey]

Will probably get away with it, but the height of the wheel/tyre will be slightly higher, therefore possibly touching the arches. Also the extra width of the tyres might touch the suspension. It's all ifs and buts, re
Can't you ask them to just supply the correct tyres for your car, if they are from a shop. Don't know why you would need longer bolts though.

Good point, never thought about that.

If the OP's wheels are factory 19's, it seems they'll be ET48
19" AMG 7 Twin Spoke wheels in 7X23 High Sheen with Gloss Black - Alloy Wheels Direct (1261739)

Edit - although he's currently got a staggered fitment

 

[ALFAitalia]

Front rolling diameter will be + 32mm / 4.75%
Rear rolling diameter will be + 40mm / 6%

Your speedo reading will be out by - 5% compared to your actual speed.

With the new setup there is only -0.52% difference in the front to rear rolling diameter so there should be no issues with the wheel speed sensor readings.

K

The speedo will probably be more acetate and the extra size will just counter the factory under reading of the speedo.

 

[SpikyMikey]

If the OP's wheels are factory 19's, it seems they'll be ET48
19" AMG 7 Twin Spoke wheels in 7X23 High Sheen with Gloss Black - Alloy Wheels Direct (1261739)

Edit - although he's currently got a staggered fitment

Aha:
19" AMG 7 Twin Spoke wheels in 7X25 High Sheen with Standard/Titanium Silver - Alloy Wheels Direct (1261740)

Still ET48

 

[SmartAmg]

The car from the pics looks like a C207. The original 19s on my C207 are 8.5x19 ET 44 all round with 235/35/19 front and 255/30/19 rear as in the OP's.
Still shouldn't need longer bolts though, No matter what the offset. You only need longer bolts if fitting spacers. You will need different bolts, if the new wheels are aftermarket, as they usually use tapered bolts, but these should be supplied with the new wheels, as opposed to ball shaped bolts on a O.E Mercedes.

 

[SpikyMikey]

The car from the pics looks like a C207. The original 19s on my C207 are 8.5x19 ET 44 all round with 235/35/19 front and 255/30/19 rear as in the OP's.
Still shouldn't need longer bolts though, No matter what the offset. You only need longer bolts if fitting spacers. You will need different bolts, if the new wheels are aftermarket, as they usually use tapered bolts, but these should be supplied with the new wheels, as opposed to ball shaped bolts on a O.E Mercedes.

Well spotted