Helgi

Hi. I was thinking about the oil thickness on my 2003 gt, on the oil cap it says 5w20 but i can see in the service book that present owner/owners have used 5w40 on it. The car is located in Iceland so we donīt have much heat here in the summer, mostly around 12 to 22 celcius. Therefor maybe 5w40 is ok or should i go the middle way and go for 5w30, also 5w20 is only sold at a "special" oil shops here who focus only in oils.

So what is your opinion? thx.

Old Mustanger

Considering where you are, I would go with the 5W20 or 0W20 from Amsoil. You only have to change this oil every 10k miles or once a year.

BLKSTANGER

/\ This 5w40 is to think for the climate you live in. 5w40 would be good to run if you lived in the middle of death valley. 0w20 would be best and then 5w20. If it's a short tripper change it out at 5k. If you do longer drives go 7.5k. I wouldn't go 10k without a UOA (used oil analysis)