I'm looking for advice as to which oil would be the best to run in my 2000 SL2 when towing. Here are the details:
Type of driving: driven very hard, 1000's of km on the track (WOT or threshold braking - only 500 km of this per oil change though), towing 1800 lb trailers (20,000+ km), daily 100 km commute (with WOT 6500 rpm shifts very common).
Mileage: 152,000 km (95,000 miles)
Oil run for first 140,000 km: Castrol GTX 5w30
Current oil: Quaker State 10w30 for "high mileage engines" (5w30 started to require a top up just before change - 10w30 burns about 1/2 as much)
Change interval: 5000 kms (3000 miles) max.
What's different is we are now planning to tow the camper on a 13,000 km (8000 mile) holiday, including up and over the Rockies (instead of many shorter trips - typ. less than 1000 kms). The engine will be running in 4th at 4000+ rpm most of the time (5th gear provides very little manifold vacuum and I don't want to sludge the engine up).
I'm thinking Mobil 1 10w30 or possibly 15w40 for three 4000 km (2500 mile) change intervals. After reading other postings I'm a little concerned about existing sludge contaminating the oil. It needs a change right now so I could swap to synth now and then change it again before leaving (will probably drive more than 5000 km before leaving).
Sorry for the long-winded post - what do you think (about the oil)?
Steve
Type of driving: driven very hard, 1000's of km on the track (WOT or threshold braking - only 500 km of this per oil change though), towing 1800 lb trailers (20,000+ km), daily 100 km commute (with WOT 6500 rpm shifts very common).
Mileage: 152,000 km (95,000 miles)
Oil run for first 140,000 km: Castrol GTX 5w30
Current oil: Quaker State 10w30 for "high mileage engines" (5w30 started to require a top up just before change - 10w30 burns about 1/2 as much)
Change interval: 5000 kms (3000 miles) max.
What's different is we are now planning to tow the camper on a 13,000 km (8000 mile) holiday, including up and over the Rockies (instead of many shorter trips - typ. less than 1000 kms). The engine will be running in 4th at 4000+ rpm most of the time (5th gear provides very little manifold vacuum and I don't want to sludge the engine up).
I'm thinking Mobil 1 10w30 or possibly 15w40 for three 4000 km (2500 mile) change intervals. After reading other postings I'm a little concerned about existing sludge contaminating the oil. It needs a change right now so I could swap to synth now and then change it again before leaving (will probably drive more than 5000 km before leaving).
Sorry for the long-winded post - what do you think (about the oil)?
Steve