Excessive oil changes

[Draigflag]

I've been trying to get to the bottom of this for a while now, I know very little about oil and the various grades etc, and as everything is so different in the US compared to the rest of the World, it's very difficult to compare.

I've been looking at modern engines and noticed the oil change intervals getting longer and longer and longer. This is to be expected with technological advances in both oil, and the refinement and additives found in fuel now. However I still hear stories around the web of people in the US changing their oil more than once a year, in fact, and it makes me shiver to say it, but even after 3000 miles!?

Most European manufactures now recommend a service/oil change every 2 years/24,000 miles, whichever occurs first. Some up to 30,000 miles, and the big trucks can do 60,000 on one oil change. Taken from VW's UK website:

" These engines use built-in sensors that continually monitor the oil quality, making it possible to enjoy reliable and confident motoring for up to a maximum of 18,000* miles or 24 months (whichever occurs first)."

Audi is the same, so is my Renault, but I can't figure out why the US change their oil so often? I appreciate almost everything in the US is pretty much controlled by oil, but the big companies wanting you to change your oil every 3k is just too obvious.

Is it to do with the oil types available in the US? Or is it to do with the amount of Sulphur in US fuel, which I've read is up to 1000% more than the fuel in the UK. Or is it just the refinement and additives in the two comparable fuels?

It kind of bugs me to think a two year old car here with 60,000 on the clock might have only needed 2 oil changes, whereas the same car in the US would have required 20 oil changes and used 10 times more oil. The US is constantly criticized for it's oil usage, but to me, there are obvious ways to cut back and this almost seems too obvious. To think each car could be using up to 1000% more in the US than each car in Europe is quite worrying.

[shanegtr]

Theres a few reasons I can think of why new cars have greatly extended oil change intervals compared to older cars:
1) Engines are becoming more efficient and generally don't load the oil up with fuel
2) Manufacuters will be learning how long they can stretch out changes to the point where it dosent affect the car within its warranty period
3) Enviromental pressure to reduce the amount of pollutants used

Oil technology hasn't greatly improved(excluding full synthetics), we have improved a lot in analysis of used oil however and that will be assisting in point 2 above. I personally am not a fan of some of the long oil change intervals a lot of new cars are using. Sure if you only have new cars and get rid of them before the warranty ends its great. But for people like me who mostly have older cars and keep them long term I believe the longer oil change intervals may be doing more harm to the engine long term. Best answer to how long the oil is good for is by doing used oil analysis. But for the long change intervals its best to use good quality synthetics as they are much better for the long haul compared to mineral, but that comes at a cost

[theholycow]

Originally Posted by Draigflag

Is it to do with the oil types available in the US? Or is it to do with the amount of Sulphur in US fuel, which I've read is up to 1000% more than the fuel in the UK. Or is it just the refinement and additives in the two comparable fuels?

No, no, and no. There's no technical need for it. Manufacturers specify longer oil change intervals here just as they do there.

It's just really great marketing by the oil and service industries. They've got the 3000 mile myth so thoroughly ingrained in US automotive culture that we get what you describe. Our junkyards are full of cars that never suffered any kind of failure or wear that could have been prevented by more frequent oil changes, with only rare examples of complete oil neglect mixed in.

Now, there is one minor technical reason I can think of. Here in the US, we can keep a vehicle on the road for much longer than can be done in places like yours with tighter regulations. For you, it might be okay to consider the engine as a wear part, as long as its wear outlasts the useful service life. In the US, useful service life is much longer, indefinite, and we like to imagine that it is infinite. Realistically, however, very few people keep a vehicle for its useful service life and most vehicles go to the junkyard before the end of their useful service life because of a lot of small repairs or a transmission failure (because somehow the oil change myth doesn't extend to automatic transmissions, which often keep their OEM fill until the end).

[trollbait]

The shortest recommended oil change interval I can think of for a new car is now 5000 miles in the US. Despite this, oil change shops and car dealers still put a next change in 3000 mile or 3 months sticker on the windshield.

Outside of some extreme cases, like driving through a dust storm, there is no technical reason to change oil at 3000 miles. People commonly do it here out of the pressure from for profit companies, or simply because that was how it was done for engines that are now several generations old.

I remember a news bit on this topic asking a racing crew pit chief how often he changed his own car's oil back in the late '80s, early'90s. His answer was 7000 miles. Taxis, even the old Crown Vic ones, would get their oil changed every 6000 miles.

The scorched bits that form in oil from being exposed to high heat are what ages the oil. They can restrict flow and even sludge up in the worse conditions. A bigger concern is that when water gets into the oil, and it will, they will mix with the water and form acids. Motor oils have improved over time to deal with scorched bits better.

Group I oils were what were in use back when a 3000 mile change interval actually needed. The cheapest engine oil on the store shelf is a Group II oil. It is further refined and purified than the Group I stuff. This gives better performance and less particle formation. Group III oils are even further refined. The majority of synthetic oils are actually Group III mineral oils(except in Germany and Japan). Group IV are true synthetics using PAOs, and Group V is anything not covered by the other groups.

Then the basic additives have improved. Being better at keeping any burnt bits in suspension, neutralizing any acids, reducing oxidation of the oil, and inhibiting corrosion of engine parts.

Even cars with shorter OCIs don't need to have the oil changed as often when using current oils. The looser manufacturing tolerances and wear may mean they consume more oil, but that consumption rate will be the same whether changed later or sooner.

As for going for longer than a year between changes. My wife's car is used little enough that it could probably go 2 years between changes. It is just easier record keeping to change it once a year, during warm weather. Besides, it sees mostly short trips, so the oil may have more water and fuel in it than a typical car's. Oil analysis is an option. I'm just not a diehard enough conservationist to save a few bucks and 5 quarts of oil a year.

[Draigflag]

Thanks all for your comprehensive answers. So it appears that cars in the US can and will go just as far on the same oil as any other car in any other country. But it seems to be more of a cutural thing to change oil too often. Perhaps like fuel in the US, oil is almost too cheap? I seem to remember seeing a roadside sign in the states readin "oil change $20" I guess with this kind of low cost maitainence, it just encourages people to do uneccesary oil changes. I think in the UK, which by the way is the most expensive place in the World to run a car, the cheapest you could get an oil change for would be around the equivelent of $170, if not more.

It's nice to know some people actually reconize this stupidity too, for a long while, every time I asked a question regarding oil changes, somone would say something like "Have you ever seen what happens to oil after 3000 miles?" and the like.

[Charon]

There is a belief that the longer oil change intervals recommended by car makers are no more than a ploy to have engines wear out sooner. The belief says that as long as the engine lasts longer than the warranty, the sooner it fails the more new cars are sold. It is probably true that frequent oil changes help engine life, but there is a point of diminishing returns. Those more frequent than necessary oil changes are wasteful both of resources and money.

Some recommend sending oil samples to testing labs for spectroscopic analysis, with the idea of determining the "proper" oil change interval. Trouble is, at least here in the USA, the analysis is likely to cost as much or more than the oil change, making saving rather illusory. And the results of testing themselves can lead to argument, since there isn't really any standard for whatever might show up. Some even go so far as to send virgin oil (straight from the container) for what is called a base-line analysis, so any changes can be identified.

The great watershed in oil change interval extension was the phase-out of leaded gasoline. The lead contaminated the oil (along with spark plugs). Once leaded fuel vanished the recommended oil change went from about 3000 miles to about 7500 miles, although makers still recommend more frequent changes under "severe operating conditions." I have seen a few places here in Nebraska which say that Nebraska's heat, cold, and dust constitute "severe operating conditions" which require the more frequent intervals.

My Toyota Tundra has a maker-specified interval of 5000 miles for an oil change, using full-synthetic 0W-20 oil. It also says if E-85 fuel is used, the interval becomes 2500 miles. That, from the Owner's Manual.

[Draigflag]

I'm a little sceptical about the manufactures making you change your oil late so the engine fails sooner theory. People these days expect good value for money regardless of brand, and reliability reputation accounts for a lot over here, and once a car brand is considered unreliable, it's can take years, sometimes decades to shake that reputation.

I'm probably going to change my oil when the car is 1 year old in December, the mileage won't exceed 12,000 but as my first 2 services are free anyway, I might as well get it done early. If I can find a place that analysis oil, then I'll consider doing this just to see if the oil would be good for another 12k.

[theholycow]

Originally Posted by Draigflag

Perhaps like fuel in the US, oil is almost too cheap? I seem to remember seeing a roadside sign in the states readin "oil change $20" I guess with this kind of low cost maitainence, it just encourages people to do uneccesary oil changes. I think in the UK, which by the way is the most expensive place in the World to run a car, the cheapest you could get an oil change for would be around the equivelent of $170, if not more.

Wow, I didn't realize that an oil change is so expensive across the pond. Is that because of the cost of the oil itself, the cost of labor, or because some laws or cultural expectations result in a more comprehensive service? Any guesses on how the costs break down?

The $20 oil change is with the cheapest oil and filter and even then may be a loss leader if the shop isn't buying in bulk (i.e. tanker truck deliveries or 200 liter drums instead of 1 or 5 liter bottles). They drain, remove and replace filter, fill, and send you on your way.

Most people probably pay more like $40 to $100. After years of doing my own oil changes with inexpensive oil, I was shocked when I went to the dealer with my 2008 VW and they wanted $90 for an oil change. An oil change like that might have $20 to $35 worth of oil, an oil filter costing $3 to $10, a complete fluid check and top-off and tire check, all chassis lube/grease service, and various stuff inspected (i.e. lights and brakes).

Originally Posted by Charon

The great watershed in oil change interval extension was the phase-out of leaded gasoline. The lead contaminated the oil (along with spark plugs). Once leaded fuel vanished the recommended oil change went from about 3000 miles to about 7500 miles, although makers still recommend more frequent changes under "severe operating conditions." I have seen a few places here in Nebraska which say that Nebraska's heat, cold, and dust constitute "severe operating conditions" which require the more frequent intervals.

And along with the 3000 mile myth, there persists a myth that "severe operating conditions" includes all normal conditions that exist in the real world, because in the beginning it was indeed defined that way. It's been decades since then and now manufacturers define normal/severe conditions much more realistically.

Originally Posted by Draigflag

I'm a little sceptical about the manufactures making you change your oil late so the engine fails sooner theory. People these days expect good value for money regardless of brand, and reliability reputation accounts for a lot over here, and once a car brand is considered unreliable, it's can take years, sometimes decades to shake that reputation.

I agree entirely. Nobody wants to be known as that company whose engines need to be replaced after 120,000 miles.

[Draigflag]

Well oil is quite expensive. To be fair I did used to use the top of the range stuff for my little Fiat Abarth, it cost £50 for 4 litres, that's around $85 USD but the biggest cost here is labour. Most garages charge £48 an hour, that's about $75 USD an hour, but one garage charged up to £148 an hour ($230 approx)

Self servicing is not an option for most people here, a lot of houses here were built long before cars existed so they don't even have a driveway, never mind a garage! Luckily I have a friend who builds and races Rally cars with his own workshop within spitting distance of where I work, so once my car's run out of warranty, money can be saved there paying "mates rates"

[trollbait]

Originally Posted by Draigflag

Well oil is quite expensive. To be fair I did used to use the top of the range stuff for my little Fiat Abarth, it cost £50 for 4 litres, that's around $85 USD but the biggest cost here is labour. Most garages charge £48 an hour, that's about $75 USD an hour, but one garage charged up to £148 an hour ($230 approx)

Self servicing is not an option for most people here, a lot of houses here were built long before cars existed so they don't even have a driveway, never mind a garage! Luckily I have a friend who builds and races Rally cars with his own workshop within spitting distance of where I work, so once my car's run out of warranty, money can be saved there paying "mates rates"

Those labor rates sound about right for an actual shop. I wouldn't want the techs at a cheap lube place doing anything more than changing my oil.

The most expensive oil on the store shelf might hit $10 a liter/quart, but I've heard of the oil for high performance sports cars, like the Nissan GT-R, costing more.