Tyre pressures

[Excited owner]

My 2004 GT was bought with 21 inch alloys (would have preferred the standard19 inch) and the tyres are Dunlop 275/35/21 front and back.

Unfortunately, this tyre size is not listed on the sticker in the door well.

I have put in 46 front and back, but not sure this maybe too much.

Can anyone advise please.

Thanks

[sandysinclair]

I think purely from memory it's 44psi front and rear rising to rear 49psi if the car has 3 passengers in it or lots of luggage or very fast commutes !! . also somewhat depends on the strength of the sidewall of the tyre, the dreadful pirelli pzeros I had on it originally were utterly lethal but the Dunlop Sport Maxx were so far ahead in grip and quietness it was a totally different car afterwards. The tyre will usually tell you, uneven wear, dishing in the middle of the tyre or one side wearing too quickly , correct geometry is vital on a car of that weight so hope that helps !

[Excited owner]

sandysinclair said:

I think purely from memory it's 44psi front and rear rising to rear 49psi if the car has 3 passengers in it or lots of luggage or very fast commutes !! . also somewhat depends on the strength of the sidewall of the tyre, the dreadful pirelli pzeros I had on it originally were utterly lethal but the Dunlop Sport Maxx were so far ahead in grip and quietness it was a totally different car afterwards. The tyre will usually tell you, uneven wear, dishing in the middle of the tyre or one side wearing too quickly , correct geometry is vital on a car of that weight so hope that helps !

That's does help, on another forum I qas a used 38 all round and the steering feels heavy.

It is just me and no luggage, so was thinking a bit more in the front less in the rear, due to the weight of the engine and steering weight. So perhaps 44 front and 40 rear

Thanks

[sandysinclair]

I think you definitely don't want under inflation as it's the best part of 2.5 tons..... and the torsen 4 wheel drive has a 60% rear bias torque split... so probably day to day 43 / 44 all around is not a bad starting point , you can always adjust for comfort on the suspension dial......

[Wight Arnage]

I hope you have told your insurers that you are running on wheels and tyres that are not compliant with the original 2004 specification.

[Excited owner]

sandysinclair said:

I think you definitely don't want under inflation as it's the best part of 2.5 tons..... and the torsen 4 wheel drive has a 60% rear bias torque split... so probably day to day 43 / 44 all around is not a bad starting point , you can always adjust for comfort on the suspension dial......

That makes sense and I think 43 may a good start,
With 38 the steering v feels heavy, thanks

[Excited owner]

Wight Arnage said:

I hope you have told your insurers that you are running on wheels and tyres that are not compliant with the original 2004 specification.

Not sure how to take that, your angle is all wrong pal, have you put simler remarks to other people as I do not find you helpful

[Mulsanne-Speed]

21 inch doesn't sound excessive to me. I'm sure my last 2020 GTC W12 (albeit the newer model) was running on 22's.

In fact I've just checked on here......... This website below suggests that the Bentley model in question did take 21's as standard, albeit on later model years - Essentially it's the same car I believe, just face lifted.

So I don't think there should be any concern regarding insurance or compatibility.

See below:

https://tiresize.com/tires/Bentley/Continental/201...

[Fiammetta]

Best to match the tyre and wheel spec with what’s listed on …..
1- the door sticker
2- if applicable it’s hand book .

It’s hand book also has a copy of build sticker in it .The same sticker found in the spare wheel well .

Otherwise you are potentially inviting a refute of claim involving a handling / braking incident .


Doubt they check the tyres if it been keyed , but they will if it’s a handling thingy .

[Excited owner]

Mulsanne-Speed said:

21 inch doesn't sound excessive to me. I'm sure my last 2020 GTC W12 (albeit the newer model) was running on 22's.

In fact I've just checked on here......... This website below suggests that the Bentley model in question did take 21's as standard, albeit on later model years - Essentially it's the same car I believe, just face lifted.

So I don't think there should be any concern regarding insurance or compatibility.

See below:

https://tiresize.com/tires/Bentley/Continental/201...

Thanks, just double checked and the tyres are 275 35 20, 102 y, sorry, previous owner got it wrong, there is no issue with these on GT a d they were standard o. 2005 models

Also the tyre pressure is similar to my previous Audi A8, which is 42 front and 34 to 36 back

[Excited owner]

Thanks, am good now and actually happier they are 20 inch, mind you the ride is so harsh over humps and pot holes, even in comfort mode

[sandysinclair]

Dude in that case I suspect something is very wrong with your suspension bags . It should be effortlessly smooth and comfortable and wafty even in the sportiest setting and biblically soft in glidey soft mode . Mine had 20inch 275 Dunlop Sports Max . You need to get that checked buddy . All the best !

[Excited owner]

Thanks

Oh dear, did not realise that, will have to get it looked into.

Not sure if I can reset anything on the car first in the meantime.