Last post on Dec 04, 2013 at 8:41 AM
You are in the Sedans
What is this discussion about?
BMW 3 Series, Infiniti G37, Acura TL, Lexus IS 350, Mercedes-Benz C-Class, Cadillac CTS, Volvo S60, Audi A4, Acura TSX, Car Comparisons, Sedan
#15734 of 16982 Re: Oil [dino001]
Mar 05, 2013 (4:10 pm)
I always thought synthetic was only useful for engines that 'used' it; akin to premium fuel...only engines that ran hot (turbo's, etc) benefited. The life of the oil wasn't necessarily greater.
Suppose it doesn't matter...to maintain your warranty you need to use what the manufacturer specifies anyway; hopefully they get it right
#15736 of 16982 Re: Oil [dino001]
Mar 05, 2013 (5:21 pm)
Oil commentary from edmunds- yes edmunds
My favorite line is "Synthetic oil is better for your car's engine and it improves your fuel economy. Myth"
For those of you who are leasing- and put synthetic in the car even though its not mandated I would think 2x before spending the extra coin on a car you don't own- for those of you who get the "free" BMW oil changes who cares on the 3 changes you will need.
I own my car - I do 2 oil changes a year and use a synthetic blend- no real reason why I choose it - it's cheaper then full synthetic and cost 10 bux more a change vs the regular and it makes me feel good for some odd reason-
#15737 of 16982 Re: Oil [sweendogy]
Mar 05, 2013 (5:44 pm)
I would have to check the manual, but I assumed my Acura (2013 RDX with the 3.5l) used semi-syn. I know my 2007 Volvo S40 uses that (I asked when I took it in for the first time last year).
but for the Acura, it will get what they put in it, since the dealer will be doing it.
#15738 of 16982 Re: Oil [markcincinnati]
Mar 05, 2013 (11:34 pm)
Are you saying that synthetic oil has a shorter (in miles or time) life span of "protection" but that semi-syn is better in that regard? I thought that one of the hallmarks of 100% synthetic was that it was able to hold more dirt and crud in suspension than non-synthetic oils (meaning, I assume) that you could use synthetic oil for longer intervals without engine damage or for shorter intervals for even better protection than non-synthetic oils.
No, it doesn't have a shorter life span. It's more than double, in fact. The issue is what happens when both are put under stress or are reaching the end of their lifespans.
Synthetic oil is slippery goo that is only protecting the engine's internals due to the anti-wear additives that are part of it. When those run out, the goo essentially has the protection of water, or close to it. If you are near the end of its life and, say, it's a cold winter day, the synthetic has all gone down into the crankcase other than a thin film left on the internal parts. If the levels of anti-wear additives are too low, you're in trouble as there is nothing to fall back on.
Natural oil has anti-wear additives as well(to help with higher rpms and pressures), but when it reaches the end of its life, the oil itself retains a fair amount of low rpm/starting anti-wear properties as long as it hasn't suffered thermal breakdown.(synthetic oils are better in this regard) In fact, oil will retain most of this natural level of protection even when it has been reduced to sludge.
The reason you should run semi-synthetic, as GM is now recommending, though not openly (new Dexos standard), is because when the synthetic runs close to the end of its lifespan, there is something to fall back on. Semi-synthetic works for pretty much all engines and is incredibly resistant to abuse as well. That it's cheaper is also a huge plus.
And, yes, almost all other manufacturers have their oil life sensors tweaked to be very sensitive with a massive safety margin if the car is running on pure synthetic. You'll never have an issue with a Honda because the synthetic isn't even halfway to its real end of life. (use it in a lawnmower or whatever if you drain it yourself - it'll still work for that just fine, even used)
#15740 of 16982 Re: Oil [sweendogy]
Mar 06, 2013 (10:06 am)
And... nothing in that article is counter to what I was saying.
#1 is about 3K oil changes. This is of course, about *oil*, which has a certain amount of natural lubrication ability no matter how old it gets. I use conventional oil in my "commuter" car (It's almost 15 years old now) and routinely run 4 or 5 thousand miles in it with no problems. My Dad's CTS is showing that it's time to change it at about 5-7 months, typically, which correlates with what the service center mechanics now recommend.
Not a huge difference, well, other than price.... I sometimes get the feeling that we're getting scammed into buying new technology.
#2 - #5 are common sense, IMO.
#6 is absolutely correct in that you can swap right over to semi-synthetic for the extra level of protection that it affords if you forget to change the oil. Semi-synthetic is awesome stuff, IMO, that gives you the best of both worlds for hardly any more money.
#7 also was touched on in my post, though indirectly. Conventional oil is not inferior to synthetic oils in normal driving conditions. The video that the article links to on this assumes that synthetic is always superior other than price, though. Most of the press also assumes this. Nearly every claim about synthetic oil being superior is based upon racing or extreme conditions, as well, where it does make a difference.
If you are racing the car or are using a high revving engine (7-8k+ RPMs), there might be some added protection. But it's going to make no difference in your Jeep or Civic.
"Further, GM says that if a customer has an engine failure that is traced to oil or lubrication issues, and if the customer does not use dexos 1 oil in their gasoline-powered GM vehicle, that act alone could void the warranty."
Note - Cadillac originally mandated Mobil 1 full synthetic in the CTS. That they would change from full to a blend and make it mandatory is telling.
#15741 of 16982 Re: Oil [plekto]
Mar 06, 2013 (10:34 am)
If you are racing the car or are using a high revving engine (7-8k+ RPMs),
So if you have a new crop turbo engine (revs are 20K+), if the turbine bearings are lubricated by same motor oil, you better get a synthetic - which is a usual recommendation by manufacturers. The conventional oil could coke on those quicker than 3K miles.
#15742 of 16982 Re: Oil [dino001]
Mar 06, 2013 (11:12 am)
Obviously. This also affected Porsche, Mazda (RX-8), the Honda S2000, and several other cars with high revving engines. Conventional oils simply couldn't take the punishment. And as engines get to be smaller and higher revving, with more turbos in the mix, you'd need a synthetic blend as a minimum.
Look, synthetics are superior to conventional oils in every way but one. The base stock of both oils is not the same. While the synthetic has vastly superior properties in most aspects, it's also so highly refined that it provides little protection by itself (almost watery with no viscosity). Conventional oil does to a degree. Then they add the additives to it to make it the oil you and I buy. This isn't an issue at all until you get to a scenario where the oil gets too old.
In essence, there is no failure mode for synthetics. They work perfectly until they don't and the engine blows up. So "whatever, I'll change it in another month" simply is asking for trouble over time. Conventional oils just sludge up and while that's a huge separate problem, your bottom end bearings usually won't grind themselves into oblivion.
Mar 06, 2013 (12:06 pm)
Wasn't saying it was a counter- just a really short and quick and easy to read- btw I posted this before your post as a general information for those who care.
Wordy posts are hard to concentrate on- like the beak of the TL- a select few like them.
I think all cars should have oil and that oil should be maintained correctly.
Drive like you live.