cold_beer839

I am about to change the oil in my '93 GTS and wondered what the seasoned GTS owners used in their cars? I know a lot depends on your climate, time of year, and driving style. I am in NC where is averages around 90 f degress in the summer and I drive hard at times, but not too hard, just spirited.

I use Castrol GTX 10w-30 conventional in my '87 S4 and it seems to run very well.

Gary Knox

David,

I use Mobile 1 in my '94 with 70K miles. I thought the 15W50 was a bit viscous, and the 10W40 was a bit thin, so I use a 50/50 blend of these two. Gives nice 2 bar at ~650 idle hot, and gets to 5 bar at about 2400 rpm hot (summer temps, ~90 degrees F, engine temp at ~185). I like to use the thinnest oil possible for street highway driving, yet like to have full pressure, or very close to it at highway driving speeds (unfortunately, mostly ~65 mph!!!!).

Cheers,
Gary Knox
West Chester, PA

IcemanG17

I would say IMNSHO that 10-30 is too light for any 928 (short of somewhere VERY cold)..but since NC does get fairly warm....I would recommend something in a 15-50 or 20-50 weight..... I've had good luck with Mobil one in 15-50 and currently run Amsoil 20-50 racing and am very happy with it.....the Amsoil does seem to hold a bit higher pressure under high loads at high temps (think the track) than the Mobil 1 did....

But if you aren't having any type of low oil pressure warnings-problems running 10-30 in your S4....then it should be fine for your driving style in the GTS too....

In general oil is getting much lighter....with new cars using VERY light oils....my new Acura uses 5-20W and my M3 runs 10-60W synthetic (never heard of that one before)

blitz928

15w/50 will be the common oil used same as your S4.

ROG100

I use Royal Purple 15w 50 in mine.
Used to use Mobil 1 15W 50.

wds928

Currently use Mobil 1 15w/50 in the 150k mile 928GTS and Mercedes 500E. Some low oil pressure at idle on really hot days. Considering a change to Brad Penn or Amsoil 20w/50 or for higher ZDDP concentrations (more zinc and phosphorus for cam/lifter lubrication)

I currently consume about 1 quart of Mobil 1 per 800 to 1000 miles, which I believe is typical of GTS motors.

David L. Lutz

Since my rebuild I have moved over to the to other side;

Amsoil 20w-50

andy-gts

I use mobil 1 15-50 year round in KCMO and have no issues...Burns 1 quart in 3500 miles on a highe mileage 93 gts.

cold_beer839

Well, I put in the Mobil 1 Synthetic 15w-50 today. We'll see how he likes it.

I use Mobil 1 synthetic in my '04 Ford F250 5.4L 4x4 King Ranch and my wife's '07 Honda Odyssey. It has always been good oil for me.

wds928

I just changed the oil this weekend to Brad Penn 20w-50. I've sent an oil sample of the Mobil 1 15w-50 I drained to Blackstone Labs for analysis, with only 3,500 miles on it. Took the car for a test drive this afternoon and oil pressure at idle was higher at startup and was 3 bar at a warmed up idle, after a 15 minute drive.

I'm going to Virginia International Raceway this Friday for a trackday and will take notes on consumption, temps and pressure.

The Brad Penn is the same as the old Kendall GT1, with higher ZDDP content (1600 ppm) for better cam/lifter lubrication.

Bill Ball

M1 15/50 does not have reduced ZDDP. Zinc and Phophorus is 1200-1300 ppm.

http://www.mobil1.com/USA-English/Mo..._Products.aspx

http://www.mobiloil.com/USA-English/...duct_Guide.pdf

Chuck Schreiber

Royal Purple 20W50. Higher oil pressure than Mobil 1.

mark kibort

amsoil 20-50 racing

104 race days on the holbert engine! 4 races so far and 1000miles on the new stroker!
3 bar at idle and 5 at 2krpm, even at 220F oil temp

mk

bernard farquart

That's a good chart, thanks!

wds928

Bill:

I didn't mean to imply the Mobil 1 15w-50 had the zppd content of some of their other oils. My point was that my engine this summer experienced some low oil pressure when hot, upon restart during an autocross and also when running errands around town. Plus the oil pressure seemed low at highway speeds, around 4.0 to 4.5 bar, sometimes.

I wanted to try something different and my reading and research led me to the Brad Penn oil, which has a zddp content of about 1600 ppm.