Thanks Allan-- I appreciate the breakdown, but unfortunately it's not quite that easy; as with a lot of folks during the pandemic, it was only driven often enough to keep it from sitting. So it's not that I didn't want to give people accurate mileage, it's that I'd likely need to go back and see what my mileage was in late 2021/early 2022 when our lives returned to more normalcy.
ah! well.. perhaps the consumption isn't as bad as my calculation then if you're driving more than that in 2 months these days.
I forget that so many people stopped driving during the pandemic. Nothing really change for my Wife and I... "essential" (lol)
I only have taken it to the dealership for oil changes, full-synthetic since my ownership, on recommended intervals.
Hypothesis: The dealership uses cheap bulk synthetic 5w30 API SN oil for most oil change services where 5w30 is specified.
Rationale: 10K OCI's in turbo engines is asking a lot from oil. I've read a lot of "rumors" (shop techs posting stuff on BITOG and other forums) that USA dealers often just buy the cheapest semi-syn or full-syn API spec bulk oil they can get their hands on and use it in almost everything. I know that the bulk oil used at our local Volvo dealer for many years was a semi-synthetic "no-name" oil provided through a local bulk lube and fuel supplier. Where "full synthetic" is claimed, these will generally be group III base stocks with viscosity modifiers and a starting TBN ~6. There's nothing wrong with any of these less expensive oils if used at appropriate intervals in appropriate applications, but I don't believe these oils, especially in 5w30 weight, are appropriate for 10K intervals in a 115HP/L turbo crossover. (10w30 would fair a lot better if climate allows). These cheaper oils achieve 5w30 viscosity range by starting with a thin base stock to hit the 5w rating cold, and polymer additives (viscosity modifiers) to hit the 30 weight viscosity target at 100C. These polymers break down when worked hard and long in high power density engines. When those polymers break down, they leave behind sludge and gunk in the worst possible places, like ring packs and turbo bearings, and the oil left behind without its polymers gets thinner and thinner at operating temps... It's a compounding effect of the polymers gunking up the rings/bearings and the thinner remaining oil blowing right by the rings that are no longer seating properly. It wouldn't surprise me if the 10K intervals with this type of oil would lead to an oil burning engine pretty rapidly.
Is there any indication on your receipts/records that they used the A5/B5 spec oil that this engine calls for? These oils will be formulated from a higher grade base stock that achieves its viscosity range with fewer viscosity modifiers, so it doesn't leave behind as much mess, stays in grade, and has appropriate starting TBN for an extended drain interval (>8 for At/B5, >10 for A3/B4).
As a totally separate matter, I also wonder about what WEIGHT oil was put in the car by the dealer. I can see how it would be confusing for a floor technician being told to put 5w20 weight in some XC60 T6's, and 5w30 weight in others. They could get that confused in the mess of many cars passing through every day for oil changes. The "T6" badge can be found on both the newer 4 cylinder DI engines and the older 6 cylinder port injected engines. That said, I'm not sure how the SI6 would react to 5w20 for a long term OCI. I would happily run a 5w20 in it for short OCIs driven gently for the purpose of attempting to clean out rings and such but probably not more than 1-2K miles.
I had an oil consumption test performed somewhere around 70K miles after the first time I received a low oil warning. The dealership said the results were negligible but after about 6 months as stated, the oil was nearing low-level again.
"low oil warning?"
Sorry to tell you this: The only "low oil warning" system included in a 2015 XC60 T6, is the operator/owner performing routine oil level checking using the dip stick as is described in the manual for this car. In fact, it recommends checking it at every fuel fill, which, when you buy a used car, is something you should always do for the first 5-10K miles to get a feel for baseline consumption rates.
The only light on your dash about oil, is the "LOW OIL PRESSURE" light. It's shaped like a little genie lamp, because at this point, you should probably make a wish. This is known formally among gearheads as the "change engine" light. If you have seen this light during normal operation of the vehicle, then your engine has been operated with VERY LOW oil levels, so low that the small amount remaining will certainly have been cooked pretty good, probably making a bit of a mess. In most engines, this light won't come on until the oil level is well below half of the sump capacity. If its any consolation, I've seen this light a few times in my life too, it happens.... but when it does, it's important to react with some efforts to "clean up" the mess that would have been left behind by the low oil conditions leading up to that point.
I'll do some number crunching and try to publish a better calculation here. I do not often use the manual shift/engine breaking very often. My wife, never. It's her primary vehicle, but if we're together I drive. My primary is a standard transmission, and the tap shift just isn't the same
Auto's are nice for relaxed driving, and can be easier on engines in some ways, but the lack of routine engine braking leads to ring gunking problems for some engines. This was a very common problem in Cadillac's with big V8's driven by seasoned citizens at leisurely speeds all the time. Some engines develop a bad reputation because of how they are used....
Believe me-- I would love nothing more than to not have to get rid of it. I have always wanted to be a volvo owner and this vehicle is damn near perfect in what I want for a DD/family hauler. On top of that, I have my eye on a new C8 or similarly priced sports car... so I really didn't want to blow part of my budget on a new family car, ha.
As an auto enthusiast, we have always kept up on the maintenance. Again, not much use of the manual shifting, but I have never had an automatic use oil at this rate.
Have you ever done 10K mile OCI's on a turbo using bargain basement bulk oil?
