Tyre Pressures.

[onefortheroad]

I have an E220 CDI Cabriolet, staggered tyres (front/rear) 235/35/18 and 255/35/18 on the rear, and I run them all at 37 psi. On the sport edition the suspension is hard the tyres feel every stone bump however any lower and I risk cracking the alloys due to pot holes and poor road conditions.

Those tyre sizes dont seem correct. 235 x 40 x18 . Should be on the front.

 

[Buck2003]

I have now lowered the pressures to 36 psi and it seems to suit well. Slightly more feel in the steering and not as firm on the road.

I guess being an estate it also depends what weight your carrying...luggage and even passengers or towing.

 

[Buck2003]

Those tyre sizes dont seem correct. 235 x 40 x18 . Should be on the front.

It may well be I'll look later...

 

[brandwooddixon]

A lot of tyre pressures are set by the manufacturer to improve fuel economy.
If the car is unladen with two occupants you can normally get away with a reduction of 3psi for comfort.
Just be aware that with very low profile tyres you'll be reducing their resilience to pothole damage as you reduce the pressure.

 

[oldjohnny]

I am constantly on pothole watch nowdays. Some of our minor road resemble scud missile test sites.

 

[mioba]

I hit a barstesard last week. Went out next day and tyre was flat. Its like driving on the moon.
Govt wont do anything as motoring is a huge earner, damage your car - go to garage - more nuggets to No 11

 

[oigle]

Makes the combo of large wheels and LP tyres even more useless. I've just removed the 20" wheels off my new EV6 and replaced with 18" and commensurately higher sidewalls. Was 255/45/20. Now 235/60/18. Only query I have is "previous reccommended pressure was 36psi. What pressure should I put in new ones?"

 

[onefortheroad]

Makes the combo of large wheels and LP tyres even more useless. I've just removed the 20" wheels off my new EV6 and replaced with 18" and commensurately higher sidewalls. Was 255/45/20. Now 235/60/18. Only query I have is "previous reccommended pressure was 36psi. What pressure should I put in new ones?"

36 it's vehicle based , not tyre size afaik

 

[oigle]

36 it's vehicle based , not tyre size afaik

Not so mate. It's related to the air VOLUME in the tyres. Bit like pushbike tyres. Skinny road tyres are pumped to over 100psi whereas fatter off road tyres run around 45. I'm just unsure whether the new tyres will have less or more volumemetric space. Guess won't be much in it so maybe stay with 36 and see how they feel.

 

[w204benz]

Makes the combo of large wheels and LP tyres even more useless. I've just removed the 20" wheels off my new EV6 and replaced with 18" and commensurately higher sidewalls. Was 255/45/20. Now 235/60/18. Only query I have is "previous reccommended pressure was 36psi. What pressure should I put in new ones?"

Try this, it should at least be good for a ballpark figure: https://tiresize.com/pressure-calculator/

 

[onefortheroad]

Not so mate. It's related to the air VOLUME in the tyres. Bit like pushbike tyres. Skinny road tyres are pumped to over 100psi whereas fatter off road tyres run around 45. I'm just unsure whether the new tyres will have less or more volumemetric space. Guess won't be much in it so maybe stay with 36 and see how they feel.

Lol.

 

[oigle]

Try this, it should at least be good for a ballpark figure: https://tiresize.com/pressure-calculator/

Interesting. Comes up at 34 which is about where I hoped it might. Didn't give me some correct choices in comparison chart but probably of little consequence. Thanks for that.

 

[grayb]

I did find this a couple of years ago - a method for comparing cold to warm pressure increases and taking that as an indicator of too low or too high pressures. All to do with the friction on the air inside the tyre. We tried it with our caravan tyres and it seemed to work, giving a smoother tow.

The Ultimate Guide to Caravan Tyre Pressure

Don’t know what tyre pressure your caravan should have? Get essential information & advice in this ultimate guide to caravan tyre pressure...

www.followourtravels.com

 

[Jmistry]

Hello folks, new to the forum - loving it.
I have an e220d and the ride feels stiff even in Comfort mode! Could it be the tyres? (I have 19" Pirellis). Any recommendations on what could the issue and how to solve? cheers

 

[Blobcat]

Hello folks, new to the forum - loving it.
I have an e220d and the ride feels stiff even in Comfort mode! Could it be the tyres? (I have 19" Pirellis). Any recommendations on what could the issue and how to solve? cheers

Hello and welcome,

Irish roads, 19" wheels and Pirelli tyres.. a combination made in the deepest levels of Hell...

Comfort mode only alters gearbox and throttle response (unless you have the fancy suspension, (which isn't common on the W213 220d)

I'd search out some 17" wheels and tyres with 225/55 tyres and sell your 19"'s