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0-20 vs 5-20

It's hard enough to find syn 0-20.

I have two vehicles (2014 Highlander, 2011 Mazda 3) that use 0W-20. I have no problem finding 0W-20. I can buy it at Wallmart from several different manufacturers (Gastrol, Mobil-1, Valvoline, Royal Purple and a few more).


That sounds like something you take when you’re having heartburn . . .



I have always been able to find 0W-20.full synthetic oil in my area of East Central Indiana. As I have mentioned earlier, I have purchased 0W-20 full synthetic oil that meets the specifications for my 2011 Sienna for $2.69 a quart at my Rural King farm store under its housebrand RK label. The store also has full synthetic 5W-20, 5W-30, and 10W-30 in the RK oil brand. These latter weiights are available in dino oil for a dollar less. As cheap as I am, I spent the extra dollar for 10W-30 full synthetic for my lawnmowers and the oil consumption in my one mower has dropped considerably. I would bet that we will see more synthetic oil in all viscosities sold under house brand labels and regular dino oil will be more difficult to find just as non-derergent oil is hard to find today.

WalMart sells SuperTech oil, their house brand. I use it in my lawn mower. I used to use it when I needed to add oil between changes.
With my newer cars that use 0w20, I cannot detect any use of oil at all between changes (5000 mi).

Car makers that stipulate 0-20 motor oil the coincide with 10k oil changes do so with the idea you use full synthetic oil. If you use a blend in the cars that I drive, Toyota, and run for 10 k miles, you void the warranty. Anything that is not full synthetic and is not equivalent even if it is 0-20 is not suitable for 10k oil changes. That’s straight from the horses mouth. No if and or buts…not full synthetic, change at 5 k miles. What other car makers want to do is up to them. Now, if you use full synthetic 5-20 w, if you can find it, it still is not suitable for 10 k oil changes, again, you can use it, just change it at 5 k miles.

@dagosa Right! Long oil change intervals are driven by marketing and government environmental departments. The state of California is one op the culprits pushing for longer drain intervals. In Europe they work hand in hand and that has resulted in insanely long intervals which do not stand up under engineering scrutiny.

GM in England stipulates 20,000 miles or once a year for its Vauxhall cars. Although the Euro spec oils are better, I would not dream of changing at intervals that long.

Toyota had it right with 5000 miles, but feels compelled to go with 10,000 miles now with synthetic oils. Synthetic oils ARE NOT TWICE AS GOOD AS MINERALS OILS!!!

GM had to backpedal on their long interval with their oil minder due to excessive engine failures. What is NOT mentioned of course is the reduced engine life in general caused by these excessively long intervals.

I don’t look at oil change intervals as absolutes. I cannot see myself going 10 k between oil changes even using synthetic oil as @Docnick says, they are not twice as good. We have been using the 5 k oil change interval for a very long time with mineral oils. Where I use the advantage is in the following way. If we have a trip planned that may take us a thousand or two over 5 k , instead of rushing out and changing the oil before the trip, we just wait till after. And feel 7500 is a good compromise.

The State of California tested oil life in numerous vehicles. They found that 10,000 miles was satisfactory for the Cobalts in their fleet. They also found that oil change intervals over 50,000 miles was acceptable for many of the trucks and buses in their fleet. For a huge fleet like theirs, they can save a lot of money on oil, filters, and labor by changing when it actually needs to be changed and not by the old rules of thumb that had been in place beforehand.

I re read the study, and the Dept of Corrections uses a 50,000 mile change interval, Fresno and Long Beach school buses are at 36,000 miles, Fresno transit buses, DOT trucks, and state fire services trucks are at 18,000 miles. I would like to provide the reference document if I could figure out how to post a PDF file or post a link to it. There is a lot more to it than just the numbers.

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@jtsanders I teach maintenance management and reliability workshops. This topic comes up all the time and smart fleet managers know that oil analysis and cost accounting will determine what the best interval is. Commercial vehicles put on a lot of miles daily with only one cold start, so the interval will automatically be longer.

The Cal. State vehicles operate with relatively warm starts and put on a lot of miles. So the longer interval. Trucks have very large sumps that allow long drainage intervals. Motorists would not accept a 7-8 quart sump on their cars; the oil would take too long to warm up from stop and go and short trip driving.

The problem I have is that other state officials and environmentalists are now touting that is California experience applies to everyone.

The city here has standardized on 7000 miles for their busses to come in for oil & filter changes and other checks. Most of the busses are still the GM units, with the newer ones having Cummings diesels. The interval was determined by tracking engine wear and cost as well as the out of service costs of the bus not operating. Some of the managers are SAE members.

Although a large fleet (such as taxi companies) can risk the odd engine failure with a long oil change interval since the savings will easily pay for the failed engine, an individual car owner cannot run that risk. So a car owner needs more insurance and changing oil more often and getting longer engine life is the preferred modus operandi here.

The State of California tested oil life in numerous vehicles. They found that 10,000 miles was satisfactory for the Cobalts in their fleet

And I guarantee you they don’t keep their fleet vehicles much past 150k miles. Probably not much past 100k miles. For those of use who keep our vehicles over 300k miles…I’m not gambling with 10k mil oil change intervals.

It seems to me that othe Cali vehicles with similar service histories could use the same oil change intervals. A more prudent method would be to test the fleet, or a subset of the fleet, to show what works in practice for their usage patterns. I agree that other states should test their vehicles as well. While Nevada or Arizona might be sufficiently similar to California, other states certainly are not. I would expect MD or VA to do their own tests if they want to save taxpayer money.

“Motorists would not accept a 7-8 quart sump on their cars”


Most Benz engines have an 8 quart quart sump

And I haven’t worked in that h . . . hole in over 6 years

Personally, I’d rather drive a car with an 8 quart sump, versus a comparable car, with a 4 quart sump

But that’s just me


@db4690 Agree there are a few but they are upscale cars. The vast majority have 5 quarts or so including the filter and it keeps oil change costs down. I would personally be happy with a larger sump on my Toyota.

Oil capacity began to increase ten years ago. V-6 Charger and 300 hold 6 quarts, V-8 7 quarts. Camry, Highlander, ES350, RX350 with the GR series V-6 (2007 and up) 6.4 quarts. Some 4 cylinder Toyotas were increased by 1/2 quart to accommodate the 10,000 mile oil change.

Some new posters will sometimes complain that a shop quoted them $XX for an oil change not considering their engine holds 6 to 10 quarts of synthetic oil.

My 99 Nissan,held a little less then 4qts and as far as I know its still kicking along just fine(sold to a construction compsny at 70,000 miles if I remember correctly,just make sure its good oil(pennzoil),the little Tech 4s held about 3.5 qts no problem to get over a 100k on them either,I dont see the need for huge sumps,if you change your oil at decent intervals.

Agree there are a few but they are upscale cars. The vast majority have 5 quarts or so including the filter and it keeps oil change costs down. I would personally be happy with a larger sump on my Toyota.

My highlander and wifes Lexus take 6.5 qrts.

I understand the full synthetics have a much stronger film strength than a conventional oil. This is especially important with oils at thin as 0W. I personally run a European 0W40 Mobil 1 in most of my vehicles and go 5000 miles between changes. The all call for 5W30 and I have never had an issue with the 40W at operating temp. I may loose a little mileage but figure it is good insurance. If all the miles are highway and in warm weather, the oil barely looks like it needs to be changed. I am always tempted to do an oil analysis and see what is really needed. I do live on a gravel road and do lots of gravel road driving so figure dust contamination is also a concern. The pickup trucks get run in places where nothing should be run so figure that oil needs changing no matter what. The daily driver is a 1994 Geo Metro 1.0L 3 cylinder for the gas mileage. Like the Toyotas mentioned, these little engines are sludge monsters if neglected. They were a cheap car new so many people treated them as disposables and never changed the oil. Stuck rings and burned valves from stuck lash adjusters are very common. Running a quality synthetic like the 0W40 Mobil 1 seems to prevent a lot of these issues. People who run a conventional and don’t change it often are lucky to get 100,000 miles out of these little engines. Those who change them often and/or run a synthetic have gotten 500,000 miles without any major engine work before the rest of the car rots away and turns to a pile of rust. “Major engine work” is defined as anything requiring the removal of the head by the way. Those who neglected these engines and had them fail with very few miles added to the “throwaway” reputation of these cars but they will treat you well if you treat them well.

It is pretty funny that I am running a synthetic oil rated for BMW, Mercedes-Benz, and others in a Geo Metro! I personally would run the 0W20 as called for. Mobil 1 is like $24 in a quart jug the last time I checked at Wal-Mart. Most name brand conventionals are 19.99 so it isn’t that much more for the cheap insurance.


Are you telling me that Metro owners who used conventional 5w30 and changed every 6 months, 3000 miles, or whatever, had major engine problems?

I’ve never owned a Metro, but I have a hard time imagining that even 20 years ago . . . or whenever the Metro came out . . . they built an engine that couldn’t make it to 100K following the manufacturer’s oil change schedule

What is a quart jug? Is it different than a quart bottle? If someone gave me a free metro I would take it and sell it and buy a real car.

I seem to recall all my cars in the old days as having 5qt systems. With large oil filters. All the 4-bangers I’m familiar with now have 4qt systems. With filters the size of peanuts.

My gut says a 5qt system would be better, but the new engines run great for hundreds of thousands of miles without excess oil usage. Try that with a car from the '60s. So while my gut likes the idea of 5 quarts, my intellect says it’s truly unnecessary on new 4-bangers. We’ve had a number of lengthy threads on the reasons. Cleaner/better fuel, much cleaner combustion, better oil, much better ability of the manufacturers to maintain dimensional accuracy and consistency, better metallurgy, better casting and manufacturing processes, the list goes on and on.

Bottom line: my gut likes a larger oil pan, but I know that feeling isn’t based on reality for today’s 4-bangers.

I DO have a serious problem with 10,000 mile oil change recommendations. There’s no way I’d go that far between changes. But that’s a different thread. And there is a possibility, a very, very, very slight possibility ( {:smiley: ), that my aversion to 10,000 mile oil changes has no more validity than my preference for a larger oil pan…

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