I’ve always believed that any motor oil bearing the applicable SAE classification is just as worthy as the next. In fact I believe there was a Consumer Report years ago, conducted on NY cabs, that indicated there was no discernible difference in motor oils that were similarly certified. I’ve ALWAYS bought whatever oil was on sale at the time and have never had any engine problems or failures due to my petroleum frugality.
All of this was before synthetic oils came into play though.
As mentioned in a previous thread (that I can’t find) I now need to put very high mileage on a new car. I settled on a new (well new '09) Hyundai Elantra: great ratings for dependability and for fuel consumption.
Are there any conclusive studies that prove that any particular oil is in fact better at protecting an engine (high mileage - completely highway) or am I right to think that any approved oil should suffice?
Some of the people on car forums I’ve browsed are swearing by German Castrol Synthetic, weight is 0w30 but they say it is a thick oil that can be used for cars that normally run 5w30. They use oil analysis test from blackstone or others to discuss it.
I think you are better off just saving your $ and changing your oil on schedule.
Instead of “oil is oil” these days you have “conventional oil is conventional oil” and “synthetic oil is synthetic oil”. In other words, if you have a car that calls for synthetic oil, any full synthetic oil will do. Yes, there will always be people who swear by one brand or another, but in general for run of the mill use any one is fine.
Additionally, if you have a car that does not require synthetic, your car’s manual may specify a longer change interval if you do use synthetic. Some people will also say you can extend the change interval with synthetic even if the manual doesn’t call for it.
Opinions about oil types and change intervals are often quite subjective because even cheap conventional oils exceed most lubricity and longevity requirements and the manufacturers err heavilly on the side of overly frequent oil changes. As a result, unless you’re one of these people who never changes their oil (or had the misfortune of buying one’s used car), chances are you’ve never had an oil related problem.
So with that caveat, in my own opinion (which is just that), since you’re putting on a lot of “easy” miles, I’d personally say you’d be fine going to at least 7,500 miles with conventional oil, but if you wanted to you could probably double that with synthetic. So the question is, do you really feel comfortable pushing the change interval? If so, go with a synthetic. If not, stick with your short change intervals and conventional oil.
Engines are expensive. You can buy a metric buttload of oil for what one serious engine repair will cost.
There are several things to consider concerning engine oil. first of is weight. What does your car’s manual call for? 10W-30?, 5W-30?, 0W-20? Look it up and use that weight Trust me if your car calls for 0W-20, 20W-50 will not be “better” for it.
Secondly look at the API grade required (again should be listed in the manual) For gas engines it should be a letter designation such as SL, or SM. In general you can go to a later grade (SM instead of SL) but not the other way around (SL is not for engines that require SM) Use of the correct grade is just as important as use of the correct weight.
Here is a link to theAPI oil classifications. On that page you will find a link to a PDF of an explanation of the rating system.
If the owner’s manual calls for synthetic, use synthetic. The guys that designed and built your engine know more about it than you do. They aren’t calling for synthetic because they have stock in Castrol.
Now for some IMHO territory
I change my oil a bit more often than the factory schedule calls for. I do a fair amount of stop and go driving so I change my oil at 5,000 mile intervals instead of 7,500 miles. My engine would probably be just fine with the 7,500 mile intervals, but see the truisms at the top of this post.
Personally I have been using Mobil 1 as of late, but I have nothing against Castrol Syntec or another quality synthetic. Both Mobil and Castrol are excellent oils.
I am running synthetic because the factory fill on my engine was synthetic even though that is not required here, I do believe that it is better, and if it was good enough for the factory to use, it is good enough for me.
YMMV.
I haven’t picked up the car yet, but from looking under the hood, the oil cap had “5W20” on it.
I didn’t realize synthetic was so different that some engines are specifically designed for it. I assumed that synthetic oil was merely a more expensive, and therefore a possibly more protective oil. I think I’ll stick to whatever the owner’s manual says and change the oil right on, or before the scheduled mileage.
Engine sludge: Some engines are more prone to it. Synthetics are best at resisting it.
Valve timing: Some engines depend on consistent and reliable oil performance to manage valve timing. Synthetics would be called for.
Just some examples. Are engines DESIGNED for synthetics? Well, BMW takes liberties with their engine designs BECAUSE synthetics can support their designs.
Rick said the most important thing in his post but I want to repeat it: READ THE OWNER’S MANUAL. For example, mine states that, in addition to API SL 5 w 30 oil, I also need to make sure I use an oil rated for GM Spec 6049M. So far only one conventional oil I have seen uses this (and you better beleive I put in conventional oil, it’s one third the price and the car is leased), which is Exxon.
I have an '08 Elantra (same engine) and the manual states that you should change the oil every 7,500 miles for “normal” conditions and every 3,750 in “severe” conditions. Of course, when I brought it in for its first oil change at around 7,500 miles, the dealer chastised me for not bringing it in sooner, even though almost all of the miles were highway miles without so much as running the air conditioner. The service guy said something to the effect of, “I don’t know why they even put the ‘normal’ schedule in there. With dusty roads and hot weather, it really doesn’t apply anywhere in North America.” (This was in Kansas City, by the way.) I think he was just trying to sell me more oil changes, personally, but I’ve been getting the oil changed about every 5,000 miles. It has 25,000 miles with no problems now – not that that means anything.
Edit to add: Enjoy your new Elantra! I really like mine, aside from the lack of highway acceleration and a slightly rough ride, but what do you expect for $16,000? Besides, I’m getting 30+ MPG in a mix of city/highway driving.
Dirt (i.e. contaminants) aren’t the only problem with oil. Sure, you’ll get the same little metal bits sloughing off the pistons, and the same amount of dirt that slips past all your filters, but that isn’t all. Oil also degrades—conventional is more susceptible to heat degradation, for example. That degradation is what ultimately produces sludge, which produces a smorgasbord of wonderful engine symptoms. That’s why the synthetics usually last longer before they need changing.
Oils get dirty equally, but different oils have different dirt holding abilities (ability to hold/suspend dirt without significant impact). Oils also hold water.
My 1995 Volkswagon Golf parked outside overnight at -35C with 5w30 conventional oil is hard to start, takes more than one attempt, the starter must crank longer and seems to turn slower. After attempt number 3 I become worried about the battery’s ability to produce attempt number 4.
Same car, same temperature (ugh), same 5w30 rating but synthetic instead: Easier to start, under 15 second crank, starter seems to rotate faster (still nowhere near as fast as during summer), starts on first attempt.
You should also get slightly better fuel economy with synthetic, but the difference in fuel costs does not balance out the additional cost of the oil. And it probably never will unless gasoline prices rise to dizzy heights but synthetic oil prices don’t rise right along with them.
I choose synthetic for my cars mostly for its benefits at the nasty cold end of the thermometer.
My car, 2 years older than yours, says 5W20, 5W30 or 10W30.
I’d go 5W20 anywhere in Canada, personally.
On edit:
PS- Hyundai considers all of Canada to be ‘severe service’.
I don’t know if you should do 3K mile oil changes, but I know Hyundai says so.
This was my reading of the part of the manual/OEM documentation that identifies service intervals for various parts.
Anyway that uses road salt is automatically severe service for oil change purposes.
There’s also a temperature standard.
Ohio counts as severe service, per the manual and maintenance interval doc.
I live in Bogota, Colombia and have a 2006 Hyundai Elantra. The recommended oil change here is 5000 km or 3125 miles, which I do religiously. Actually, I do all the maintenance at 5000 km. Car remains like new and I don’t use synthetic oil.
Ok, just checking…a lot of dealerships will tell you that their area is considered severe service, even if it isn’t.
In fact, there was a study done once that showed dealers in every single geographic area of the country could claim their area was “severe service.” I am not sure why a comapny that manufactured cars in North America would bother to include a “regular” and “severe” category if most people’s driving falls under “severe” service. It’s like calling a snowy day in Michigan “severe” weather…it’s not “severe” by any definition of the word.
This is unmitigated baloney. The “severe” versus “normal” service has next to nothing to do with the climate-- it has to do with the kind of driving you do (stop and go, a lot of cold starts, etc). Once your car is warmed up, it doesn’t care what the outside temperature is, so the only way you would possibly consider climate is if you do a lot of short trips, in which case your car might warm up all the way in a warm climate but not a cold climate.
As for the salt, I can see why it would be a good thing to do more frequent chassis inspections on a car that lives in a place that salts, and perhaps more frequent changes of belts and hoses, but the crankcase oil shouldn’t care.