How long can one delay a synthetic oil change past 6 months?

I just had my oil changed yesterday. I think it went 18 months between oil changes. 9600 miles between changes. I highly suggest a battery tender for any hybrid. My 12V is testing good now. Before I got the tender it was moderate. I use the tender once a month.

 

My synth oil was changed in May of 2019, and then again in June 2021. Everything was fine. That said, and because of COVID and two mised driving vacations, the car had less than 5,000 miles driven between the two. YMMV.

 

it really depends on how tip-top shape you want to maintain your Prius and whether you plan on keeping it for an extended time. The longer you leave oil in the engine, the more it may build up. If you change the oil once a year, you may accumulate a tiny amount of buildup which you won't notice a difference first many years. But over time, probably about 10-15 years, things will accumulate, you'll probably notice differences in your engine, possibly burning oil then. For someone who plans to keep their car probably 5-10 years probably won't care much and your car will be fine. But for those who are hoping for the long run 10+ years, then you may want to consider changing more often.

 

With those low miles, I would not worry much.

 

Here’s something I recall from 20 years ago. BMW said not to change your oil until the car said it was time, which was mileage-based weighted by monitored driving conditions. I don’t recall the specifics, but the baseline was, say, 10,000 miles, which could change to 5 or 15k miles at the margins.

However, the problem wasn’t the oil. It turned out that the oil filters disintegrated in some cases between 2-4 years. Costly warranty repair. After that BMW said the longest you should go was 12 months.

We’re putting on 2,500 miles a year on our Prius. I’m doing 6 month service intervals right now because it’s on Toyota’s dime still. Afterwards will go to annual changes.

 

In the old days Toyota minimized plastic waste and emissions in Prius manufacturing. True pioneer. 6months oil change interval is horribly far from that. Used engine oil goes to rycycling of course but still. I honestly think that 6months interval has more to do with getting the cars to shop and minimizing overall field failure rates rather than longetivity of engine. All at the cost of customer and..nature

 

dealers have a lot of control. ford and gm are overwhelmed with anti ev dealers due to lack of maintenance revenue

 

Yes, the more cars visit shop the less field failures and reliability ranking keep on shining And it’s good money too. About a quarter of automotive industry profits used to come from aftersales. EV’s are changing that dramatically