I checked and my car (Audi Q5) can use either. My last service they put in 5w-40 oil but I can only find 0w-40 oil at my market (oil that also meets Audi’s strict standards…I don’t understand it all but it has the right certifications printed on the label).
I know I can add the 0w-40 to the engine even if 5w-40 was used before with no problems.
My question is, should I work harder to find the 5w-40? It seems the 0w-40 is better in cold weather but in Chicago temps are pretty moderate with only a few really cold days. 5w-40 seems good for towing or hauling but I never do that. Yet the Audi service center used 5w-40 which I assume they did cuz they know better than me (I sure hope so).
Big deal? Not a big deal? My car is in great shape (looks almost new) but it is 13 years old with 130,000 miles on it so I want to be sure it gets the best treatment it can and keep going.
Not a big deal. If you are using a synthetic and following Audi’s change intervals, you’ll be absolutely fine either way. The 5w might have a marginal advantage in lubricity, but the quality of the oil is far more important.
I live in Ohio. Purchased a 2005 Saab 9-5 in 2015 with 75K miles. It now has 260K miles, and I change the oil every 5K miles using 0W-40. Engine runs fine, and doesn’t burn oil.
As a general matter, The difference between 0w-40 & 5w-40 only matters to engines that are often started in very cold temps. As in -20F & more. If your local dealership service dept thinks 5w-whatever is thin enough for local winters, then decent bet there’s no reason to go thinner.
And explicitly there’s no harm in going thinner. Once up to operating temp, 0w-40 & 5w-40 have the same lubricating characteristics; that of 40w traditional oil.
The first number in the specification of a multiweight viscosity oil is the viscosity when the oil is cold, like at startup. You want the oil to be thin enough to lubricate all the parts but not too thin. At startup this is heavily dependent on the ambient temperature, which can range from below zero to 90+ deg F in Chicago.
So 0W-40 might be better for cold winter starts than 5W-40. But the latter might be slightly more protective in hot weather starts.
As @LSLGuy said, they will behave identically once up to operating temperature.
As for “Audi’s strict standards,” any oil that has an API “starburst” symbol and meets the requirements of the designated API performance level in your owner’s manual will be fine. With that said, synthetic oil is higher-performing and lasts longer. Note that 0W-40 oil is likely only available in synthetic.
Thanks but not sure what “starburst” means. When I was looking it up I read that Audi really wanted “VW 502 00, 504 00, or 507 00” oil. I did not see that on a lot of brands as I was looking. Seems a European thing (maybe?) and the oil at Home Depot was not listing that. I went to Amazon to get some and the oil I got said it was for European cars so maybe not common in the US? I dunno…
Mostly I just get my car serviced so never deal with this. In this case I was about to head out on a long road trip and noticed my oil was low(ish) so wanted some oil on hand just in case since I did not have time for the service appointment.
Oil designators beyond the viscosity numbers are a dog’s breakfast of competing standards. What Audi (and all the others) really want is a spec that says “you must you our branded oil that costs 3x as much as anything without our brand on it”.
VW 502 00, 504 00, or 507 00 are Volkswagen-specific part numbers for their special branded oil. Getting to the equivalence of what SAE or DIN or oil industry standard code gives the same performance is quite a shell game. On purpose. The bastards.
It’s the Euro oils that are a crazy quilt of proprietary and competing standards. The US and Japan standardized under the API/ILSAC set of standards, so usually the latest API standard is equivalent to the latest ILSAC (Japanese) standard. And they’re backwards compatible - an old car requiring API SG oil will do fine on modern day API SQ or anything in between. So you can buy a Japanese car and use commonly available US oil of the latest spec without worry.
Meanwhile there are multiple VW gasoline engine oil standards and they’re not necessarily backward compatible, for example 508.00 and 511.00. And MB has their own set, as do Porsche, Fiat, Peugeot, etc..
Its one of those situations where the US got it right in a lot of ways and the European overcomplicated things I nthe name of optimal performance. German engineering indeed.
The funny thing is as I was reading along nodding my head I saw “an old car needing” and anticipated seeing “SD”. Then I read “SG”. WTF is SG? Then I got to the end and saw SQ. WTdouble-F?
Been a long time … a long damned time, since I worked on drove a US car.
Actually, those designations appear to be VW/Audi manufacturer-specific standards, which is not something done by American or Japanese carmakers (which all use the API/ILSAC standards).
The Mobil 1 oil you bought apparently meets a wide range of performance standards, including API SL through SP, as well as VW 502 00. So you are good.
I’m at the mercy of the oil change place, since I don’t do my own oil changes. And now that synthetic is so common that they buy it in bulk, there aren’t even any containers I can see to verify what they’re putting in.
I can only hope and assume that when I’m paying for synthetic of a certain viscosity, that’s what I’m getting. There’s no real way to tell without wiping down the dipstick and sending the residue to a lab. I presume they wouldn’t risk their entire business by perpetrating fraud. The receipt certainly confirms synthetic along with a bunch of other incomprehensible gibberish.
Then they bring the dipstick to you to show you that the oil level is full and the oil is clean. Nice ritual, but it’s obviously useless. It tells me nothing about the quality of the oil, or if they even bothered to change the oil filter. It’s inevitably all about trust.
It’s very convenient because it’s fast – drive in, get it done, drive out, without even getting out of the car. But I’d feel better getting a trusted mechanic to do it.