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[toii]

I have changed from standard run-flats to Goodyear Eagle F1 Asymmetric. Should the tire pressures be the same as documented for the standard run-flat tyres?

[buckshizzo]

Yes should be the same.

[jadatis]

You can re-calculate it with spreadsheet I made, in wich I use the same formula that the European car- and tyre-manufacturers use .
http://cid-a526e0eee092e6dc.skydrive...0tyre-pressure
In this map the spreadsheet and examples.
And if you cant work it out , give me the needed data , and I will calculate it.
There is a chanche that the runflats have a diferent load-index then the new tires. The reference-pressure used in the formula is probably the same, because normal car tires , so 2,5 bar or 36 psi.
If those data of the tire are the same, the pressures stay the same.

[toii]

Originally Posted by jadatis

You can re-calculate it with spreadsheet I made, in wich I use the same formula that the European car- and tyre-manufacturers use .

Thanks for your reply. Unfortunately I couldn't figure out how to use the spreadsheet . These are the input values I think are needed. The front tyre is 225/40 R18 and rear is 255/35 R18.

The maximum permissable axle-loads for front: 985kg
The maximum permissable axle-loads for rear: 1065kg
The maximum-speed of the car: use 160km/h
The advice-pressures for normal front/rear: 2.2/2.4 bar
The advice-pressures for heavy load front/rear: 2.4/2.8 bar
Camber angle: unknown
Kerb weight of vehicle: 1625kg

The maximum load of the tire: 670kg
The reference presure of the tire: Extra load (says 340kPa max)
The letter that stands for the maximum speed: Y

[jadatis]

I filled in the spreadsheet for you and will place it in the map as exampletoii.
filled in the max speed to get the about the same pressures, because I asume your car can go faster because of the Y tires. Then the advices in my sheet come out about the same as you have given me. That explaines, why for up to 160km/h it can be much lower,for the savety of the tires. For lesser fuel consumption you may put them higher, but you loose grip and comfort.
It is your own responcibility, not to go over the speed and loads the advices are given for, otherwise your tires can get damaged.
The calculating back of the loads they used for normal advise goes wrong here for the reason I wrote in front of it, so cant be trusted, but I estimated a save weight and filled it in at "your own input".
Had to chanche some fields from LBS to KG.
Also asumed your car to be frontwheel-drive ( always motor in front)
for the weight dividing for normal use.
Mind that the advice pressures are for the weigt and speed it calculates for.
And it must be seen for those weight as a minimum pressure for the weight and speed it is calculated for.
By using a high enaugh weigt, you sertainly wont go over for the use they are given for, the tires wont get damaged if the weigts stay under that.

edit: I had problems with uploading the file, something with the server , the message sayd .
But now I uploaded it and you can see it.

[toii]

Thx jadatis, the skydrive service where you have saved the file is not online at the moment so I will try and access later. Yes the car does go a lot faster than 160km/h : damn these speed limits!