Retrofitting TPMS to a 2014 W212 Eclass AMG

[Mike.Dibley]

Hi
I have an Eclass AMG Sport registered April 2014. IT DOES NOT have TPMS fitted. Does anyone know if I can easily retrofit this and if so will my Command system pick it up?
Secondly, if I fit TPMS how do I get the (TYRE PRESSURE LOSS WARNING SYSTEM) removed or disengaged as I believe this is integrated with the ABS ?
Thirdly, I want to fit 19" wheels (car has 18" AMG Wheels presently) and wonder if either monitoring system will show a fault if I do so!
The rims are aftermarket but to the same dimensions, apart from offset as the optional AMG wheels offered by Mercedes.

 

[stevehg]

You'll have to check with a star specialist to see if tpms receiver is fitted to all and can be activated. If not you can still go for a retro fit kit. If it can be done, you just need to buy 4x compatible Schrader sensors. They are about £50 each or you can source from MB dealer parts ~£80 each. They auto configure after about 10-15 mins of driving.

The TPMS sensors will work on any wheel and tyre combination. For ABS etc, you typically have about 3% leeway in rolling radius. So if you are using a size that is the same as factory option, you'll be fine. By the way, the offset will make no difference.

Thanks

Steve

 

[Mike.Dibley]

Thanks Steve
Do you mean that with the TYRE PRESSURE LOSS WARNING SYSTEM installed presently, that fitting alternative 19" wheels together with MO recommended tyres I should be OK even though I guess the car system will be set up presently for 18" wheels.

 

[whitenemesis]

The compulsory tyre pressure warning system is software/firmware based and works irrespective of wheel/tyre fitted. There are no sensors fitted to the rims.

There's is a second system, optional, that does use sensors on each rim. This system reports actual psi for each tyre in the cluster. Clearly sensors will need to befitted to any replacement rims fitted.

If you buy sensors and have function enabled via Xentry (which will require SCN coding from M B Germany) then the compulsory tyre pressure loss function will be over ridden.

Personally I wouldn't bother paying £60 a rim for sensors that aren't easily transferable and only last a few years.

 

[scgfull]

The compulsory tyre pressure warning system is software/firmware based and works irrespective of wheel/tyre fitted. There are no sensors fitted to the rims.

There's is a second system, optional, that does use sensors on each rim. This system reports actual psi for each tyre in the cluster. Clearly sensors will need to befitted to any replacement rims fitted.
.

Not sure where you are getting the "optional"/"compulsory" from. As far as I have been able to find out some form of monitoring system is required. I do not believe the law mandates either "Indirect" or "Direct".

"Direct TPMS:
methods use pressure sensors to measure pressure in each of the four tires. Then these sensors transmit the pressure data via a wireless RF transmitter to a central receiver. The receiver communicates to a display that informs the driver which tire is underinflated. The tag in each wheel is designed to send a warning signal when a tire’s pressure drops below its specified safety level. Under-inflation has been cited as a cause of tire failures such as tread separation or tire blowouts. It is also responsible for shortening tire life and reducing fuel economy.
Indirect TPMS:
Indirect systems employ wheel speed sensors on a vehicle’s anti-lock brake (ABS) system to track each tire’s rotation. The premise is that under-inflated tires have a smaller radius, resulting in a higher rotational speed compared with a fully inflated tire. The sensor is supposed to detect the faster rotation, and the system alerts the driver. In practice, this change in radius is small, making indirect measurement less reliable than direct pressure measurement."

When I ordered my new E350 I did not get any option on TPMS. The TPMS on my car is the "Direct" version with the sensors in the tyre.

Steve

 

[stevehg]

Thanks Steve
Do you mean that with the TYRE PRESSURE LOSS WARNING SYSTEM installed presently, that fitting alternative 19" wheels together with MO recommended tyres I should be OK even though I guess the car system will be set up presently for 18" wheels.

Yes, I did. No need to go for MO tyres though just those that are the right size. The system you have detects a sudden change in rotation rate for a given speed. I don't have personal experience of how the MB system works as I have the full TPMS system on mine, but with previous experience of another car, Audi, with this type of ABS based system, you have a reset button that you are suppose to use when you change pressures or set of wheels/tyres. So you just fit your 19" wheels and tyre, reset system and then it will work as normal.

For your other systems like ABS, ESP etc to work properly, guidance is to pick a wheel/tyre combination that is within 3% of the rolling radius of the factory fit.

Cheers

Steve

 

[Mike.Dibley]

Yes, I did. No need to go for MO tyres though just those that are the right size. The system you have detects a sudden change in rotation rate for a given speed. I don't have personal experience of how the MB system works as I have the full TPMS system on mine, but with previous experience of another car, Audi, with this type of ABS based system, you have a reset button that you are suppose to use when you change pressures or set of wheels/tyres. So you just fit your 19" wheels and tyre, reset system and then it will work as normal.

For your other systems like ABS, ESP etc to work properly, guidance is to pick a wheel/tyre combination that is within 3% of the rolling radius of the factory fit.

Cheers

Steve

MY PRESENT WHEEL SET UP (2014 Mercedes E350AMG Sport)
FRONT 8.5J x 18 H2 ET 48 (245/40 R18 97Y XL POTENZA TYRES)
REAR 9.0J x 18 H2 ET 54 (265/35 R18 97Y XL4 TYRES)
MERCEDES HANDBOOK SHOWS AN OPTIONAL WHEEL AS FOLLOWS
FRONT 8.5j x 19 H2 ET48 (245/35 R19 93Y XL POTENZA TYRES)
REAR 9.5J x 19 H2 ET48 (275/30 R19 96Y XL TYRES)
I WANT TO FIT ALTERNATIVE NON STD WHEELS AS FOLLOWS
8.5j x 19 Offset 45 front (I THINK TYRES SHOULD BE 245/35/19)?
9.5J x 19 offset 45 rear (I THINK TYRES SHOULD BE 275/30/19 OR 265/30/19???)


THE BELOW ARE THE TYRE COMPARISONS
OPTION ONE
FRONT WHEEL Like for like comparison with handbook but changing from an 18” wheel to a 19” aftermarket wheel with a lower profile tyre and a different wheel offset (3mm less than original)
Existing set up 245/40/18 width 8.5 offset 48
New setup 245/35/19 width 8.5 offset 45
EXISTING NEW
Diameter 653.2mm - 654.1mm
Circumference 2052.1mm - 2054.9mm
Poke 60mm – 63mm
Inset 156mm – 153mm
Speedo error 0% - -0.14%
Reading 30mph 30mph – 29.96mph
Reading 60mph 60mph – 59.92mph
Ride Ht gain 0mm – 0.45mm
Arch gap loss 0mm – 0.45mm

Conclusion, (front wheels): Compared to your existing wheel, this new wheel will have an inner rim which is 3mm further away from the suspension strut. The outer rim will poke out 3mm more than before. Speedo reading will under read by -0.14%



OPTION TWO
REAR WHEEL Like for like comparison with Mercedes handbook showing Mercedes wheel size changing from an 18” wheel. NOTE However I am fitting an aftermarket 19” wheel with a lower profile tyre and it has a different wheel offset (3mm less than original NOTE IN THE HANDBOOK ON THE 19” WHEEL THE OFFSET REDUCES TO 48 FROM 54)
THIS IS THE TYRE THAT MERCEDES SUGGEST FOR THEIR 19” WHEEL BUT I AM NOT SURE HENCE OPTION THREE​

Existing set up 265/35/18 width 9.0 offset 48
New setup 275/30/19 width 9.5 offset 45
EXISTING NEW
Diameter 642.7mm - 647.6mm
Circumference 2019.1mm - 2034.5mm
Poke 66.3mm – 75.7mm
Inset 162.3mm –165.7mm
Speedo error 0% - -0.76%
Reading 30mph 30mph – 29.77mph
Reading 60mph 60mph – 59.55mph
Ride Ht gain 0mm – 2.45mm
Arch gap loss 0mm – 2.45mm


Conclusion option two: Compared to your existing wheel, this new wheel will have an inner rim which is 3.3mm closer to the suspension strut. The outer rim will poke out 9.3mm more than before. Speedo reading will under read by -0.76%
​

OPTION THREE
REAR WHEEL Like for like comparison with Mercedes handbook showing Mercedes wheel size changing from an 18” wheel. NOTE However I am fitting an aftermarket 19” wheel with a lower profile tyre and it has a different wheel offset (3mm less than original NOTE IN THE HANDBOOK ON THE 19” WHEEL THE OFFSET REDUCES TO 48 FROM 54)
THIS IS NOT THE TYRE THAT MERCEDES SUGGEST FOR THEIR 19” WHEEL BUT IN MY OPINION OFFERS THE LEAST SPEEDO ERROR ALTHOUGH THE SPEEDO WILL OVER READ SLIGHTLY
Existing set up 265/35/18 width 9.0 offset 48
New setup 265/30/19 width 9.5 offset 45
EXISTING NEW
Diameter 642.7mm - 641.6mm
Circumference 2019.1mm - 2015.6mm
Poke 66.3mm – 75.7mm
Inset 162.3mm –165.7mm
Speedo error 0% - 0.17%
Reading 30mph 30mph – 30.05mph
Reading 60mph 60mph – 60.1mph
Ride Ht gain 0mm – -0.55mm
Arch gap loss 0mm – -0.55mm

Compared to your existing wheel, this new wheel will have an inner rim which is 3.3mm closer to the suspension strut. The outer rim will poke out 9.3mm more than before. Speedo reading will over read by 0.17%​

​

These are my three options.​

Option one goes without saying and based on your info I guess there is no problem​

Option two is what Mercedes suggest in the handbook for the larger wheel​

Option three to me seems the more logical as the errors are less than option two but I guess option two should be adopted as this is in the handbook. If I understand you all once fitted the command system should just be reset so I don't know why the dealers seem so reluctant to offer any comment other than don't do it!!!!​

​

 

[whitenemesis]

Not sure where you are getting the "optional"/"compulsory" from. As far as I have been able to find out some form of monitoring system is required. I do not believe the law mandates either "Indirect" or "Direct".

"Direct TPMS:
methods use pressure sensors to measure pressure in each of the four tires. Then these sensors transmit the pressure data via a wireless RF transmitter to a central receiver. The receiver communicates to a display that informs the driver which tire is underinflated. The tag in each wheel is designed to send a warning signal when a tire’s pressure drops below its specified safety level. Under-inflation has been cited as a cause of tire failures such as tread separation or tire blowouts. It is also responsible for shortening tire life and reducing fuel economy.
Indirect TPMS:
Indirect systems employ wheel speed sensors on a vehicle’s anti-lock brake (ABS) system to track each tire’s rotation. The premise is that under-inflated tires have a smaller radius, resulting in a higher rotational speed compared with a fully inflated tire. The sensor is supposed to detect the faster rotation, and the system alerts the driver. In practice, this change in radius is small, making indirect measurement less reliable than direct pressure measurement."

When I ordered my new E350 I did not get any option on TPMS. The TPMS on my car is the "Direct" version with the sensors in the tyre.

Steve

EU regs require new cars to be fitted with some form of tyre pressure monitoring. The default is software based.

 

[stevehg]

Compared to your existing wheel, this new wheel will have an inner rim which is 3.3mm closer to the suspension strut. The outer rim will poke out 9.3mm more than before. Speedo reading will over read by 0.17% [/CENTER]

​

These are my three options.​

Option one goes without saying and based on your info I guess there is no problem​

Option two is what Mercedes suggest in the handbook for the larger wheel​

Option three to me seems the more logical as the errors are less than option two but I guess option two should be adopted as this is in the handbook. If I understand you all once fitted the command system should just be reset so I don't know why the dealers seem so reluctant to offer any comment other than don't do it!!!!​

​

Hi Mike

Personally, I would go for option 3 as the wheels you plan to use have an offset of 45. The reason your current rears have a greater offset of 54 is to compensate for a .5" wider wheel and 20mm wider tyre and also to give the staggered look.

FYI the offset calcs for options 2 is wrong, as you have reduced offset from 54 to 48 for your current 18" rears in the assumptions.

Cheers

Steve

 

[Mike.Dibley]

Hi Steve
Offset changed to relate to current wheel set up can you or anyone else advise further please
Thanks


PRESENT WHEEL SET UP (APRIL 2014 Mercedes E350AMG Sport)
FRONT 8.5J x 18 H2 ET 48 (245/40 R18 97Y XL POTENZA TYRES)
REAR 9.0J x 18 H2 ET 54 (265/35 R18 97Y XL4 TYRES)
MERCEDES HANDBOOK SHOWS AN OPTIONAL WHEEL AS FOLLOWS
FRONT 8.5j x 19 H2 ET48 (245/35 R19 93Y XL POTENZA TYRES)
REAR 9.5J x 19 H2 ET48 (275/30 R19 96Y XL TYRES)
I PROPOSE TO FIT ALTERNATIVE NON STD WHEELS AS FOLLOWS.
8.5j x 19 Offset 45 front (I THINK TYRES SHOULD BE 245/35/19)
9.5J x 19 offset 45 rear (I THINK TYRES SHOULD BE 275/30/19 OR 265/30/19???)
The latter appears to offer least speedo error but the Mercedes handbook suggests the 275/30?


THE BELOW ARE THE TYRE COMPARISONS COMPLETED ON LINE. THEY SHOW THE DIFFERENTIAL BETWEEN THE PRESENT WHEELS SET UP AND THE PROPOSED NEW SET UPS FOR 19” RIMS USING TWO ALTERNATICE SIZE TYRES FOR THE REAR . ALSO AS MY OFFSETS ON THE NEW WHEELS DIFFER TO THOSE OF THE PRESENT MERCEDES WHEELS I AM KEEN TO ENSURE THAT THE CHANGES DO NOT INTERFERE WITH THE COMMAND SYSTEM. THE CAR DOES NOT HAVE TPMS FITTED TO TYRES.
FRONT WHEELS
FRONT WHEEL Like for like comparison with handbook but changing from an 18” wheel to a 19” aftermarket wheel with a lower profile tyre and a different wheel offset (3mm less than original)
Existing set up 245/40/18 width 8.5 offset 48
New setup 245/35/19 width 8.5 offset 45
EXISTING NEW Variance
Diameter 653.2mm - 654.1mm +0.9mm
Circumference 2052.1mm - 2054.9mm +2.8mm
Poke 60mm – 63mm +3mm
Inset 156mm – 153mm -3mm.
Speedo error 0% - -0.14% -0.14%
Reading 30mph 30mph – 29.96mph -0.04mph
Reading 60mph 60mph – 59.92mph -0.08mph
Ride Ht gain 0mm – 0.45mm +0.45mm
Arch gap loss 0mm – 0.45mm +0.45mm

Bottom of Form​

Compared to your existing wheel, this new wheel will have an inner rim which is 3mm further away from the suspension strut. The outer rim will poke out 3mm more than before. Speedo reading will under read by -0.14%

MY CONCLUSION IS THAT THERE SHOULD BE NO PROBLEM WITH THE FRONT WHEEL ROTATION



REAR WHEELS
Existing set up 265/35/18 width 9.0 offset 54
OPTION ONE 275/30/19 width 9.5 offset 45 (new wheels)
OPTION TWO 265/30/19 width 9.5 offset 45 (new wheels)

VARIANCES HAVE BEEN CALCULATED FOR OPTION 1 & 2 IN RELATION TO EXISTING

EXISTING NEW OPTION 1 Variance NEW OPTION 2 Variance
Diameter 642.7mm - 647.6mm +4.9mm 641.6mm -1.1mm
Circumference 2019.1mm - 2034.5mm +15.5mm 2015.6mm -3.5mm
Poke offset 60.3mm - 75.7mm +15.4mm 75.7mm +15.4mm
Inset 168.3mm - 165.7mm +2.6mm 165.7mm +2.6mm
Speedo error 0% - -0.76% -0.76% 0.17% +0.17%
Reading 30mph 30mph - 29.77mph 0.23mph 30.05mph +0.05mph
Reading 60mph 60mph - 59.55mph -0.45mph 60.1mph +0.1mph
Ride Ht gain 0mm - 2.45mm +2.45mm -0.55mm -0.55mm
Arch gap loss 0mm - 2.45mm +2.45mm -0.55mm -0.55mm


OPTION 1 & OPTION 2
Compared to your existing wheel, this new wheel will have an inner rim which is 2.7mm further away from the suspension strut. The outer rim will poke out 15.4mm more than before. Speedo reading will under read by -0.76%

MY CONCLUSION IS THAT THERE SHOULD BE NO PROBLEM WITH THE REAR WHEEL ROTATION BUT THAT THE 265/30/19 TYRE WOULD BE THE BETTER OPTION ANY COMMENTS PLEASE AS MERCEDES SUGGEST THE 275/30/19 TYRE & NOT THE 265/30/19?