Struggling with 10,000 mile oil change intervals, but want to!

My beloved Prius has 25,000 miles on it. I have changed the oil every 5,000 miles until this point. I do a mix of driving but my daily commute is only 6 miles each way. I also do a fair amount of highway driving. I don't know if this would qualify for extreme or severe driving conditions. I last got an oil change in May and now have 5,000 miles since then. I'm toying with now changing my oil every 10,000, but am worried about the effect this may have on my engine. I also have a 3,000 round trip planned for October and would hate to leave with 6,000 miles on the oil. A part of me wants to just go to 10,000 for short term budget reasons and not wasting money. Thoughts on this matter are greatly appreciated.

I'm sticking with the factory recommendation, but I intend to get rid of the car just short of 100.000 miles. If I felt like trying for 200,000, I might change my tune.

I have done the 10k interval for the last two "cycles." Although this is not scientific, I remember hear some clattering and increased engine noise towards the end of the 10k interval. I may go back to a 5k interval this time.


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I plan to keep my car well beyond 100k miles. So, I change my oil every 5k miles even though I understand that the UOA indicates you can go well beyond 10k miles and Toyota recommends 10k miles.

My reasons are mostly peace of mind and it gives me a reason to put the car on ramps and inspect the underside of the engine twice as often. I recycle the oil so do not consider this wasting oil.

What brand and weight of oil is in it now?

I've never thought much of 10k mile intervals, but they work for a lot of people. I would most definitely use a big-name synthetic if you plan on going 10k miles per change.

World population is approaching 7 billion people, which means there are approximately 7 billion different opinions on proper oil change intervals. If 5,000 mile intervals lets you sleep better at night, then by all means do it. With that said, I usually follow what the manufacturer recommends. I will continue to stick to 10k oil changes in the Prius unless for some reason my driving style changes to include much shorter trips, gravel / dirt roads, or any of the other conditions where Toyota recommends shorter oil change intervals.

For what it's worth, I had a '79 Cadillac that required 12,500 mile oil change intervals. The car had 200,000 miles on the odometer when I got rid of it. Read between the lines.

I don't think there would be any measurable difference in two 200,000 mile motors where one had 5K changes and one had 10K changes, as long as you use good quality synthetic oil. Old habits die hard. 10K is just fine.

It took me quite a while to accept that as well. Took years for me to go from 3K to 5K. Now I'm at 10K for all my cars ... no issues at all.


REV

There's no problem with running to 10K miles between oil changes with Mobil 1, and I've noted no additional engine noise toward the end of each oil change interval. I'm up to 41,ooo miles now. I use TRD oil filters, which are better quality than the standard items. I've posted all my used oil analyses (UOA) from running mine for 10k oil changes since it crossed 1oK miles. I've also done intermediate oil analyses at 15K and 25K. All of them show that the engine is in good shape and the oil can go longer than 1oK miles per change.

Don't worry about the 10K oil change interval unless you're using non-synthetic oil.

I haven't noticed any change in engine sound towards the end of the 10K interval either ... with ANY of my cars.

Although I wouldn't do it without knowing test results first ... I bet you'd be fine running today's top quality dino oils 10K as well.

REV

Over on the Gen-II forum, a Prius Chat member just got some feedback from Toyota USA, basically saying the drain interval should be kept at 5000 miles as a relatively high priority.
(the original question was: can Gen-II switch to 0w-20 they said yes but hold the drain interval). Dunno if same comment would apply to Gen-3 as Toyota gave no rationale for their recommendation.

I am struggling with this too as I have the Mobil-1 Extended Drain Interval in there now.

Start doing UOA's to gain some confidence about the engine and oil conditions, and let that guide you on longer drain intervals. I've sucked out some oil from the dipstick tube to send in between oil changes.

When new, my 2010 Gen 3 already had Toyota 0-20 synthetic oil, but they still recommended 5000 mile changes.
The next two changes were at the new recommendation of 10,000 miles. I am pleasently supprised that at 10,000 miles the oil still looks like new. just getting a bit of a slightly darker tint that makes it a little easier to see on the dipstick.

I have used Mobil 1 synthetic oil and 10,000 mile oil changes for near 30 years, but have had oil go from baby oil clear to about maple syrup color in 10,000 miles. I did oil analysis in the early years which always showed the oil good for many more miles at 10,000.
I have never seen anything like the Prius 1.8 on that synthetic Toyota oil. The oil looks better at 10,000 miles than some of my older rigs on Mobil 1 did at 4,000 miles. Much better ring seal in the Toyota I suspect.
Great stuff, I am confident that the prius engine will last about forever with that oil at 10,000 mile changes.
My driving is summer and winter driving with temps from +100 to -30F with a few miles of gravel road thrown in every trip as I live several miles off the nearest paved road.

I have been using the high-VI, Toyota 0w-20 stuff, not the Mobil 1.

I think I will go ahead and go to 10,000 this time. My oil right now at 5,000 miles is a little darker than the color of honey. Does the oil level go down as it approaches 10,000? Also, is it true that the color of oil does not have much to do with it still working and doing it's job? Another question that I have is that my car has whatever the Toyota dealership put in it at 20,000. Is that oil high enough quality to go 10,000 or do I need to switch to something like Mobil 1?

Age-old debate about which is better, the Toyota oil or Mobil 1. Both work fine for 10K oil changes. Mobil has had springtime sales on Mobil 1 in the past, and I've stocked up.

Oil getting dark isn't a bad thing, it's the details of how the lubricants in the oil are holding up. It's good to check the oil level on a regular basis on a level surface (or on the same surface), otherwise you'll see some variation in oil level that's not real. Prii don't use much oil, really shouldn't use any at all.

What oil you've got in your engine can be a problematic question - there's no easy way to tell the difference between non-synthetic and synthetic oil by looking at it. Check your paperwork from the dealership oil change for evidence that they used synthetic oil. If you can't clearly determine that, change the oil yourself at the 5K mark and put in synthetic. There have been reports on this forum of dealerships that are careless about which type of oil they use in their oil changes. Doing it yourself means you KNOW what's there.

How do you change the oil since the car is so low? Do you use ramps?

Yes. I use the low profile Rhino Ramps. I bought mine at Advance Auto when they had them on sale one time.

I am at 93,000 miles and plan on putting 300,000 miles on this car. I am going stick with 10K oil changes.

My last Toyota had 305,000 miles when I sold it and it never burned oil near the end.

I do notice a little more noise when accelerating hard in my 2003 Honda CR-V when I'm near 9k miles on the Mobile 1. So now I just change it's oil at 9k mi before it gets noisy.
That car does have 160k miles on it now and I've only been using synthetic since it hit 110k mi so that probably has something to do with it...