Checking up on my '07 S60 (132k) over the weekend and noticed my coolant levels were a little low. Volvo recommends using only Volvo coolant but I was wondering what others use. Do you stick with Volvo coolant or do you use other brands?

Also, general question, last week I did an oil change and used Mobil 1 synthetic extended performance (15,000 miles). My work commute is 2 miles or less and I generally don't drive my car very often. Can I really wait until I hit 15k miles before changing it again? That could take around a year to hit...

Thanks!

 

You need to give the car a decent hot run occasionally to avoid the motor sludging up.

Whilst synthetic oil is better overall sludge caused by condensation / moisture buildup will occur when you only do short runs. The engine fails to reach an optimum running temperature.
Sludge buildup will be noticed inside the oil filler cap or on the oil dipstick and can look a bit like butter.
It is sometimes mistaken for a blown head gasket but that is more likely to look like foamy coffee color.