just found out that my wheels are 225/40/18 with et 35 , is this the reason my rear keeps bottoming up with a full load or on a bend and what et should they really be

 

is it not due to the tyre profile being to big

 

Depends on what yaer your car is.

AFAIK the classics should have a max size of 225 35 18.
40 profile will make the rolling radius too big.

The offset is supposed to be 48 IIRC.

 

sorry forgot to mention its a MY01, I took it to R-Tec in Hatfield and they said it should be at least et45. Its got eibach springs on but dont think its been lowered and they have fitted 19s on some WRX's

 

IIRC, the ET number is the distance in mm from the wheel hub face to the center of the wheel, so for +ve values, the lower the number the further the wheel sticks out. So it could be catching on the wheel-arches, but it shouldn't bottom out on the suspension! The biggest problem with the wrong ET number is usually very bad handling!

 

yea its just catching on the arches not bottoming out

 

Thats your problem then! You neet to get wheels with the correct ET number. The whole setup of the car is made based on the standard ET number, so any changes will result in handling imbalances, so you should never really fit anything outside the manufacturers specifications.

 

the 18's were already on there when I brought the car, I phoned the garage and they said they could put the originals back on but they are 17's and the silver coloured ones and at the moment I got black multi spokes with polished rims

 

ET48 on a Classic, not so sure about new age.