With my low mileage, OK to skip this year's SYNTHETIC OIL change?

I would have no reservations about waiting until March.

Don't forget to check the dipstick at the next opportunity; top up as needed.

Admirable.

 

It's just as likely that the sump was deliberately overfilled to give you an extra buffer in case of unexpected consumption. This has become a near-ubiquitous practice at all kinds of service shops in the USA, since most drivers are terrified of lifting the hood and pulling the dipstick.

There is no penalty in minor overfilling apart from the cost of the extra oil. I suspect the shops are eating that cost in trade for fewer claims of forgetting to fill the oil at all. Most of those claims come from unnoticed consumption or leakage in the first place.

In sum, the dipstick isn't a precise instrument. If it looks close, it is. And that's good enough. Hence the oft-repeated advice to wait until it is clearly a whole unit (quart, pint, liter etc) low before topping up.

 

Oh good, another oil change thread! Yes, I am in the wrong forum, but that question applies to all generations of Prius.

For the last 40 years, I have always checked my oil after the engine was cold for several hours. But then I read, (I think in the owners manual) to always check the oil when the engine is warm. It said to turn off the car, wait five minutes, and then check the dipstick. Either way, the most important thing is to check it on a regular basis.

The Gen 4 manual says to change the oil every 10,000 miles, or 12 months, whichever comes first. I believe the other generations say to change every 5000 miles / 6 months?
If you are a low income retiree, you might want to keep an eye on the dealer website and see when they have oil change specials.

You will get lots of replies, pro and con. And a few arguments here and there. Some experts claim the oil properties break down, even if the car is not being driven much. Others may suggest you put in the "extended mileage" type of oil, such as Mobil 1-- supposedly guaranteed for 15,000 miles between changes. But that would mean buying and bringing your own oil to the dealership. Or, possibly finding a private shop that will change your oil cheaper? Have you checked Walmart? Can we trust Walmart? Their price is $44 for synthetic, here in California. And you can choose any brand of oil you want.

With the low miles that you drive, it probably won't hurt your Prius c if you go one year between synthetic oil changes. Not sure I would be comfortable stretching it out any longer than that. I am no expert. Just an average Joe retired Prius driver.

 

One can "get away" with a lot of postponed or skipped maintenance but "pay me now, or pay me later" comes to mind.

With low mileage and living where the weather goes from HOT to COLD fairly frequently, water accumulation in the crankcase is a concern.......along with some of the additives breaking down.

Truth IS that you probably could let it go for 2 full years with no noticeable harm.
In fact some people consider it a badge of courage that they NEVER change their oil once they put synthetic in.
OK maybe not never but something like 5 years or 50,000 miles.

IF.......you plan to keep the car a LONG time, I think it could be penny wise and pound foolish.
Could be.
Having the change done at a "real" shop gives them an opportunity to check some other important stuff too.

The gamble might be really small......but a gamble none the less.

 

As a retiree, trying to save money where I can, I sure wish I could find a private shop, and not the dealer, to do my oil changes. I don't trust those "quick lube" places. I don't even trust Walmart, but I just happened to be in there and saw the prices. And the guy said that I would probably have to bring my own oil filter, because they don't service many Prius in there.

Heck, to be honest I don't even trust the Toyota dealers to do it.

 

cut back on the donuts?

 

i think every other year will be fine.

 

As hard as I try... the temptation overwhelms me. It's my little treat in life.
Back to the oil ("Earl") thread....

 

i'm concerned about your health buddy.

 

Since you are near mickeys funland, Hybrid Pit is in your back yard.

@sfv41901 and @RightOnTime run it and probably could be the shop that you are looking for to avoid the dealer.

I bet they might work with you a bit on oil changes.

 

That depends on how often you drive.

There are basically three main reasons motor oil goes bad and should be replaced: 1. The oil itself degrades, 2. the additives degrade or get used up, and 3. it becomes too contaminated with fuel, water, and other combustion byproducts.

For typical driving conditions, miles driven is a reasonably good approximation of oil and additive degradation and depletion. But contamination usually occurs at a much faster rate just after a cold start. So after about a year of daily cold starts, the oil becomes significantly contaminated, even if you drive only a couple miles each day. Hence the typical recommendation to change the oil every X miles or Y months, whichever comes first.

But if you don't drive daily, then it would be somewhat longer before the motor oil is so contaminated that it should be changed. A better metric might be the number of cold starts instead of months. For example, as a conservative guesstimate, you could change it after 240 cold starts instead of after 12 months.

 

I've always viewed the manufacture's recommended engine oil replacement intervals as the cheapest, easiest, and probably best ways of keeping a car running well. So on the occasion that my vehicle reaches the 12 month point before the recommended mileage, that's when it gets replaced, along with a new filter. I believe that contaminants and lubricant degradation are the main justification.

 

That sums it up very nicely.

 

I'm trying Carson Toyota for the first time. (Home of Dianne Whitmire, Priuschat member & Toyota fleet salesperson.) I brought my own Mobil 1 oil, and the service writer gave me a great discount off the oil change. Much better than other dealers.

While I'm here, I might just buy this Hybrid RAV 4.

 

I'm sure you could take it to March with no problems. I would expect zero extra wear on the engine or anything like that, going over the time limit generally does not directly contribute to engine wear. However, the problem you will run into is a cumulative one. Even the "synthetic" from the dealer will leave some deposits and deposits usually happen at a greater rate as the oil ages, particularly with the acids and water that build up.

There's a reason they spec a mileage and a time interval. Mileage is pretty much self explanatory but it does vary GREATLY depending on mostly highway vs mostly city, more than they will ever admit but that's for another discussion. The time limit is there for those that don't drive their cars a lot which sounds obvious but maybe not. A big part of it is for what I hinted at, highway vs city. It's assumed and almost always true that if you easily hit the time limit before the mileage limit you're most likely doing all short trips, possibly never getting the oil up to temperature to vaporize the water and some other contaminates so they build up. On top of this, your engine has been subjected to way more cold starts, higher load on average, and several times more total revolutions than a car that's mostly freeway driven at the same mileage.

The time limit is valid and it can be argued that it's as important as the mileage limit. Luckily with a fuel injected car that's in good running condition and especially one that's up to full (coolant) temp and in closed loop operation super quickly like the Prius, you can likely exceed the time limit by a good bit. And again, being a cumulative build up of issues like sludge, one time going over the limit is unlikely to hurt a thing, ever, it won't significantly contribute to sludge or ring land deposits. Doing it for the car's whole life is another story. If you don't already, it might be a good idea to take it for a 20-30 minute drive, freeway if possible if you plan to stick it out on this oil. .

 

Oil change every 10k??? Why does the maintenance signal go on after 5k???

I also check Groupon for deals on oil changes. Might get a free tire rotation or car wash.

 

Check fluids and tire rotation.

 

Refer to the maintenance manual...


Every 5k miles, rotate tires.
Every 10k miles, change oil.

Maintenance light goes off every 5k miles to remind you to do... something.