What weight oil do you guys run in your 993? (with hydraulic cams that is)
10-17-2007, 06:37 PM
#46
10-19-2007, 10:22 AM
#47
Also please repeat for me please. What amount of EOS (which I have almost a case of) should I add to 12 qts of Mobil 1 15w-50 SM (which I have several 5 qt jugs of 
) ?? Is it one bottle (pint?) of EOS per oil change( which is aprox 10 qts of fresh oil)? Or is it 1 &1/2 oz per quart of oil ? Sorry that I'm staying confused, but I seem to stay that way on this subject .
Glenn
) ?? Is it one bottle (pint?) of EOS per oil change( which is aprox 10 qts of fresh oil)? Or is it 1 &1/2 oz per quart of oil ? Sorry that I'm staying confused, but I seem to stay that way on this subject .Glenn
10-19-2007, 11:49 AM
#48
Rennlist Member
Thread Starter
Sure, no problem. For those of you that still have some EOS, 1 bottle of EOS to a fill with either m1 0w40 or m1 15w50 (either EP or non-EP) should give you sufficient Zn and P.
Alternatively, you could always use 50% M1 MX4T 10w40 and 50% M1 0w40 and get a healthy ~1400ppm Zn and P. Same goes with the 15w50 and blending it with the M1 V-Twin 20w50.
Alternatively, you could always use 50% M1 MX4T 10w40 and 50% M1 0w40 and get a healthy ~1400ppm Zn and P. Same goes with the 15w50 and blending it with the M1 V-Twin 20w50.
10-19-2007, 01:59 PM
#49
RL Technical Advisor
Yessir. 
This issue is not about lubrication and wear prevention; this is about flushing the byproducts of combustion from the engine to prevent the smallest orifices in the engine from becoming obstructed with foreign matter.
If the majority of one's driving is all highway miles, then oil change intervals can be extended to 5K-6K. For city use when short trips are the norm, I tell my customers to change their oil so they don't need my services, at least for that.
This issue is not about lubrication and wear prevention; this is about flushing the byproducts of combustion from the engine to prevent the smallest orifices in the engine from becoming obstructed with foreign matter.
If the majority of one's driving is all highway miles, then oil change intervals can be extended to 5K-6K. For city use when short trips are the norm, I tell my customers to change their oil so they don't need my services, at least for that.
10-19-2007, 09:00 PM
#50
Charles and Steve, THANKS for answering (repeatedly !) all these questions about oil for our air/oil cooled Porsches !!
10-19-2007, 09:41 PM
#51
Steve/Charles,
Is there any validity to this....
..."not sure switching brands and grades is a good idea. Seals are conditioned (damaged) by the oil. Changing to a new formula risks further "conditioning" of the seals."
Is there any validity to this....
..."not sure switching brands and grades is a good idea. Seals are conditioned (damaged) by the oil. Changing to a new formula risks further "conditioning" of the seals."
10-19-2007, 09:49 PM
#52
RL Technical Advisor
It really depends on the oil chemistries in use,....
Most oils do not cause oil leaks any longer, in and of themselves. Oil leaks that occur after changing oil brands or types are usually caused by solvent action that scours carbon-sludge-dirt away that covers the seals-gaskets-O-rings on the inside.
A worst-case scenario might be where someone went from a "dirty" oil (Pennzoil/Quaker State/Castrol) to a synthetic that has a high detergent content.
Most oils do not cause oil leaks any longer, in and of themselves. Oil leaks that occur after changing oil brands or types are usually caused by solvent action that scours carbon-sludge-dirt away that covers the seals-gaskets-O-rings on the inside.
A worst-case scenario might be where someone went from a "dirty" oil (Pennzoil/Quaker State/Castrol) to a synthetic that has a high detergent content.
10-19-2007, 09:54 PM
#53
It really depends on the oil chemistries in use,....
Most oils do not cause oil leaks any longer, in and of themselves. Oil leaks that occur after changing oil brands or types are usually caused by solvent action that scours carbon-sludge-dirt away that covers the seals-gaskets-O-rings on the inside.
A worst-case scenario might be where someone went from a "dirty" oil (Pennzoil/Quaker State/Castrol) to a synthetic that has a high detergent content.
Most oils do not cause oil leaks any longer, in and of themselves. Oil leaks that occur after changing oil brands or types are usually caused by solvent action that scours carbon-sludge-dirt away that covers the seals-gaskets-O-rings on the inside.
A worst-case scenario might be where someone went from a "dirty" oil (Pennzoil/Quaker State/Castrol) to a synthetic that has a high detergent content.
Understand. What would we do without you? Walk around dazed and confused mumbling to ourselves, with these questions gnawing at us. Your presence is truly appreciated.
10-27-2007, 08:45 PM
#54
Deer Slayer
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Mobil-1 15w-50 in summer, Mobil-1 10w-40 in winter. I put the 10w-40 in today and it purrs. SL rated on both. I change the oil in October and March, which works out to about 3500 miles between changes.
10-27-2007, 11:03 PM
#55
Drifting
10-28-2007, 06:56 PM
#58
We use Mobil-1 15/50 in 993 engines and either Mobil-1 15/50 or Kendall GT1 20/50 in 964 or 911 engines. For the 996/986 we use Mobil-1 0/40
As posted by Thaddeus, we also recommend spring and fall oil changes.
As posted by Thaddeus, we also recommend spring and fall oil changes.
