Originally Posted By: 1998malibu
My 1998 Maliby only has 120000km on it and I've been using Castrol GLX all this time, changing the oil twice a year. I'm about to be driving close to 5000km a month and I'm thinking it would make sense to switch to a synthetic.
CT in Canada has 100% synthetic Formula 1 5W30 50% off right now, and I'm thinking of stocking up. Any reason not to proceed?
If you want the longer drain interval, go with the synthetic.
The Castrol oil is just fine though, if you want to keep using it.
However, a 50% off sale is a great reason to try the F1 synthetic. Why not???
My sis-in-law has a 96 Monte Carlo(3.1), had 120k miles when switched to Mobil 1, no problems to report. Engine running strong(now 181k miles)
On a 3.1 though, keep an eye on the coolant level/oil levels.
The intake gaskets can leak internally, which is bad news for the engine bearings, and can hydrolock the engine in extreme cases. The good news is that FelPro makes a newer style gasket which can help fix the problem. Ive done this repair on several 3.1s, usually over a weekend(with lots of breaks/goofing off)
