Hello!
I have a question about oil grades and brake fluids. The manual for my
1994 Pontiac Trans Sport specifies that an oil like 5W30 or similar (all ending in 30) must be used, and that the brake fluid should be DOT3. But the workshop at the local dealer's (there's only one where I live, Canarys islands, Spain) says that 5W40 is just great, and that DOT4 brake fluid is "just like DOT3 but improved". It seems odd to me that the manual (and caps on the car) should insist on the other numbers. Can anyone give me an opinion? Is there much difference between DOT3 and DOT4? Does it not matter if the oil is thicker?Thanks for any help!
Marianne
P.S. Apologies if this comes through twice.