[Guest]

I switched from Castrol GTX 5W30 (winter viscosity) to Mobil 1 10W40 last weekend, and it seems that the cars rev's freer, gets better gas mileage (15% over two tanks, but 5% is probably from slightly warmer weather), and in general just runs smoother...

Am I just imagining this? Or is synthetic just better?

I realize that there are many synthetic vs. mineral oil threads, but I couldn't help it..

 

[Slott]

I switched mine over to Mobil 1 synthetic about a week ago and I've noticed that the car revs freer as well although I don't know about the gas mileage. I don't think you're imagining things

 

[SacoMan]

Ive always heard synthetic is way better than mineral, in fact you cant find mineral oil in supermarkets or car specialiced shops in Spain.

It was sold ages ago but now even old cars run synthetic