when to switch to max life oil for high mileage 2014 prius

"hi mileage oil" includes additives to make old oil seals swell up a little bit, which can stop or reduce leaks.

You don't have any leaks, so don't bother yet.

 

Sad thing is, these oils are invariably marketed as being mandatory beyond some mileage, and usually quite early. I recall reading the label of a high mileage oil, thinking I better switch, due to miles alone.

 

Well how many miles do you think a 2Z engine in hybrid detune State is going to stay non-burning engine oil with crappy oil control rings installed? Being at 200 plus thousand you're doing pretty darn good I'm not sure how far you think this is going to go I guess it's driving style and car usage has a lot to do with it a lot of Prius owners aren't really going anywhere to work and back and to the supermarket maybe twice a week or what have you doing things like that a vehicle with even those crappy things installed in it could go 500,000 mi. There's just a lot of variables. When I was working in the industry I had access to oil all the time I could change my oil every 8 days if I wanted to and I had some vehicles that got treated like that didn't make any difference in how long they lasted this was back in the late '70s and early '80s I had an endless supply of oil All I wanted avgas too All I wanted I ran vehicles on avgas and rebuilt engines and got to see valves and heads pulled apart after engines have been run pretty much proprietarily on avgas didn't make a whole lot of difference like all the claims people would say how clean high octane Av gas would keep an engine. I can tell you from tearing down the engines personally not so much the case they were a tad bit cleaner but nothing that would jump out and hit you in the forehead like magazines and advertising was touting in those times. In the mid '70s on a 2TC hemi-head 1600 engine in a Corolla I would regularly get 350,000 mi. One of the first ones I owned was when I was a teenager I never changed the oil in that car for about 15 years I just unscrewed the filter and topped up the oil No kidding I swear to God that car ran to over 345,000 mi. With absolutely no issues.

 

Switch to high mileage oil if and when your oil consumption starts getting “significant”, say from a cup or two every 5k, to a quart or two. It’s a stop-gap measure; the oil has additives to swell rubber (and synthetic equivalents). Won’t help with piston rings but may help with deteriorating valve guide seals, for example.

 

You want
To
Go to synthetic blend? Thought full synthetic was newer oil technology above blended?