I have a 2001 Toyota Sienna minivan I bought brand new. I have always used Valvoline oil and changed it every 5K to 6K miles, but never let it go over 6 months. At 115K I switched to Valvoline Max Life full synthetic oil. With all I read/hear about synthetics vs. conventional motor oils, I wonder----AM I WASTING MY MONEY ON THE EXTRA COST???
Typically I would say yes you are spending more money than needed. Here is the catch, the Toyota engines (nearly all V6 and most I4) of your vintage were known to sludge up if oil was changed every 5-6k with conventional. If oil change interval reverted to 3k most were fine with conventional. The 5-6k interval was fine with synthetic. In your case stick to same interval with synthetic every 6 months or 5-6k miles.
The original “Normal service” oil change interval for the Toyota engines that had the sludge problem was every 7.5K miles. Once Toyota admitted the problem, they sent letters to all affected Toyota owners recommending they lower the “Normal service” interval to every 5K miles.
The above was with dyno oil. Toyota’s letter did also support the use of synthetic oil. I agree with andrew_j’s comments that synthetic is less prone to sludge.
We have one of the “problem” Toyota engines on our 99 Sienna van. The oil gets changed every 5K with dyno oil. No sludge problems (145K miles).
With this engine I agree…keep using synthetic. Synthetic oil is a LOT LESS susceptible to sludge. You’d have to really abuse a engine to get any kind of sludge using a good synthetic oil.
Agree; if I owned that model Toyota, I would use synthetic and change the oil every 3000 miles maximum for mixed urban driving. This would avoid sludging and make the engine last the 300,000 miles without internal work.
I think you are wasting your money. With the sludge problems this engine is known for, I would use a conventional “high mileage” oil and change it every 5,000 miles. That is what I do with my mother’s 2002 Sienna and it has worked just fine.