Oil Change Interval
I own a 2015 Toyota Sienna van. The warranty is almost up. My question has to do with the oil change interval shown in the maintenance manual. It stipulates a 6 month/5k miles interval between changes...
Forum Discussion
mr. ed wrote:JimK-NY wrote:
The 6 month oil change policy comes from Toyota and other manufacturers. I have no idea why that is necessary and what data supports the requirement. Personally I cannot understand how oil is going to deteriorate sitting inside the engine.
It's true. Oil itself doesn't deteriorate but certain additives can. Plus, there is contamination from other sources inside the engine (combustion byproducts, for example).
So engine oil additives deteriorate over time and additional deterioration occurs due to exposure to combustion byproducts. I would think those same factors would cause deterioration of expensive synthetic oils. Many of us are not going to see any improvement in longevity with synthetics because they will still need to be replaced every 6 months.
