variable oil consumption

[flyboy4947]

I ahve run both GC 0W30 and Mobil 1 0W40 alternatively in a 2002 Audi 1.8T engine. OCI is 5000, with GC consumption is less then 1/4 qt per OCI, with Mobil 1 varies between the same and up to 1 qt. Has anyone else noticed this difference? Driving is mostly highway, very little wot, all oil analysis seem to match up with the exception of iron being higher with Mobil 1 which seems pretty normal mileage on car is 125,000, has run synthetic since new.

 

[moribundman]

Oil consumption in my '96 A4 with the 2.8 V6 12 valve engine (162k miles, somewhat worn valve stem seals*) varies considerably depending on choice of oil and on driving conditions. Oil consumption ranges from 1/3 of a quart to >2/3 of a quart per 1,000 miles. Stop&go city driving greatly contributes to oil consumption. Most oil consumption is due to oil being trapped in the PCV system after the engine has been shut off. This oil is burnt once the engine is started up. The engine consumes the least oil when the car is being driven long distances at highway speeds (for which this car was built).

Full synthetic oils show increased consumption over Group III oils. Highest oil consumption occurred with M1 0W-40, lowest with Castrol 5W-50 (and Chevron Delo 400 15W-40).

*The engine used very little oil until it loosened up noticeably at around 75k miles. Until then oil consumption was less than 1/4 quart per 10k miles (with Castrol 5W-50).

 

[flyboy4947]

What is funny is that the oil consumption has been basically 0 since new to 125,000 with only Mobil 1 showing any consumption, GC never. Guess the additives in thse two are easy on the valve guide seals, etc.

 

[jessefrank]

I have 54k on my 02 A4 1.8t and I too have noticed that M1 (0w-40) seems to disappear.
It seemed to start with the car @ around 30k miles. I'd didn't have to add any at first (but noticed the oil did go down on the dipstick a bit) and then up to 1/8-1/4 quart over 3-4k OCI's. I switched to Penzoil Platinum European 5w-40 and the consumption stopped. I have also used Castrol Syntec 5w-40 since with no consumption over about 4k OCI's.
I used to be a die hard M1 user..but don't use it any more in the A4 or my Nissan Titan (noticed more upper engine/valvetrain noise w/ M1).

 

[Audi Junkie]

Mobil 1 SS does burn off easily.

1.8ts don't really burn oil much and actually run well on 30 weight, as long as excess oil temps are avoided. When I used GC, especially in my Audi V6 30v, consumption was seriously lower than other oils, as good or better than 15w-40. I ran GC 11k/6 months back-to-back, a while ago when I was paying for dealer services and stretching my OCIS out.