Those who use 30 weight oils...

[toyota62]

Hi.
We use Castrol FMX Magantec 10w-30 for the last 6 years at work with out a single oil related problem.
very thin w30 oil 9.6 at 100c'
Summer temperature up to 42c'
This oil goes in 5.7L gas Chevy suburban to 1.4L Holden XC barina.Some of the vehicles have passed 200000km mark.

 

[Zaedock]

1992 Jeep YJ Wrangler 2.5L I4:
Castrol GTX 5W30 (winter)
10W30 or Chevron Delo400 SAE30 or 15W40(for the hot summer trail rides)

2004 Chevy Malibu Maxx LT 3.5L V6:
Whatever-in-my-stash 5W30 or 10W30(summer)

1959 Willys CJ5 134ci I4 "F"-head:
10W30 or SAE30

1998 Chevy Tarcker 4 door 1.6L I4:
5W30(winter) or 10W30(summer) if it's really hot, I use 10W40.


Tonttu, I've seen your other posts too.
Trust your American friends!
Now, repeat after me: 10W30 will not harm my Firebird...say it over and over again and you'll be fine. Also, as a former ASE certified tech, I recommend you find another mechanic.

 

[twentynine]

First thing first.

Dodge 5.7L, spec 5w-30, 10w-30 suitable. For the last oil change I used Trop Artic syn-Blend 5w-30. In the past I have used Motorcraft 5w-30 and Super Tech full syn 10w-30, Pennsoil 5w-30 Truck and SUV. I can see no difference. All looks about the same, engine sounds and runs the same. Gas mileage 17.5-18 (MPG) on the highway a solid 16 in town.

Secondly

Reach over to the other side of the car and open the glove compartment, get the owner's manual and used the oil suggested in the manual. If you don't have an owner's manual,their are at least 100 web sites dealing with the Firebird, Camaro, engines. Giving you the benifit of the doubt because you are in Sweden, I would say a good quality 5w- or 10w -30 will work very well in your engine.

 

[addyguy]

2002 Chevrolet Cavalier 2.2 OHV I-4, 66,000 miles/105,000 km:

5W-30, differet brands, changed every 5,500 - 6,000kms, 0.5-0.75 litre used between changes.