AndyH
Well-known member
Synthetic oil doesn't provide a longer oil life by itself. Engine oil is 75-80% 'base oil' and 20-25% additives. The additive package is depleted in use while the base oil is not.JeffN said:I've driven on gasoline about 11,000 miles in the last 1.5 years and the car tells me I still have half of my oil lifetime remaining. I'll get it changed when the 2 year limit comes up in Decembe, as recommended due to calendar aging. Part of the good oil life is due to use of synthetic oil and the other part is that most gasoline burning on the Volt will be done on the highway. Oil lifetime is hurt more by short trips on the engine during city driving and repeated cold engine starts and the Volt's EV range tends to reduce the need for those versus a conventional or non-plugin hybrid. The Volt's engine computer keeps track of your usage pattern and uses that to calculate the estimated oil life.drees said:I think you can go something like 2 years between oil changes if you don't use the engine much. The car watches how the engine is used and adjusts the OCI for you so they are generally a rare event. Even without running the engine much, the oil can accumulate water and stuff which you want to remove.
Not running the engine is worse than start/stops, because the engine still 'breathes' each day - exhaling during the heat of the afternoon and inhaling overnight. Enough water condenses out of the air to cause engine rust, acid formation, and thus deplete the oil's rust/corrosion and acid-neutralizing additives.
I wouldn't go two years between oil changes without oil analysis at the one year, 18-, 21-, and 24-month point so I knew exactly what was happening. And there is absolutely no way I'd do it with any off-the-shelf oil - even Mobil 1's best 15,000 mile (normal service) product.