968 engine / motor oil
01-20-2015, 12:21 AM
#1
Rennlist Member
Thread Starter
968 engine / motor oil
My new to me 95 968 made it to the bay area today from Lugna beach Calif ,yea!!! I am wondering what brands and weights the other RL's 968 owners are using in their 968 for motor oil. Im currently using Mobil 1 20/50 VR 1 motorcycle oil in the 911 and a 50/50 blend of VR 1 20/50 and Mobil 1 15/50 in the 951. Thanks guys.
01-21-2015, 01:04 PM
#4
Rennlist Member
I have been using Miller Oils Motorsports series in my race car. Very happy with it so far. Matching a proper filter is almost as important.
http://performanceracingoils.com/eng...c-3_26_24.html
http://performanceracingoils.com/eng...c-3_26_24.html
01-21-2015, 08:00 PM
#5
Drifting
I would only use a 5W-40 in a 968 if the" MAX" ambient temp is + 10 deg cel( 50F) , meaning the outside ambient temp range would be from minus 20 deg cel( -4F) to a MAX ambient temp of + 10 deg cel ( +50F) & even then once I get the engine oil up to operating temp I would never go for full power at Max RPM
Remember , the 968 and its oil circuit is little different to the 951( deep last century engine design ) , meaning if the oil pressure at normal & slightly above "Hot" engine oil temp ,at high RPM you are putting no 2 conrod bearing ( big end bearing ) at extreme risk , because the oil pressure is way too low at high RPM = BANG
Plus, if I was to use a 5w-40 oil vis , I would search out a oil that is high in ZDDP AW package , which is not common in a "this" century oil like a 5w-40, most 5w-40 oils have to meet this century emission protocols of low levels of ZDDP = lower oil film strength
And in relation to ZDDP & 968 / 944S/ 944S2 twin cam 16V engines over the last 10 - 15 years we have only seen ( at our independent Porsche specialist shop ) massive cam lobe wear & hydraulic lifter face wear & cam chain sprocket wear ( these are part of the cams ) if these cars were on low oil film strength oils ( mainly 5w-40 or 10w - 40 ) engine oils
Remember the 968 , like the 944S & 944S2 has very high load flat tappet design & to make matters more interesting the pointy end of the cam lobes are unusually sharp / pointy & most important of all , this area is only lubricated with NO OIL pressure at all , the cam lobes + the timing chain / sprocket are lubricated by splash only , hence the extreme importance of Oil Film Strength
How do we get high oil film strength ?
Answer }
A ) increase oil viscosity , say from 5w-40 to 20w- 50 if both oils had the same amount of ZDDP , which is nearly never the case because the last century 20w-50 vis is allowed to have higher levels of ZDDP for last century cars & the 968 is a last century car/engine
B ) Increase the levels of ZDDP( AW package)
So a 20w-50 a good ZDDP AW package is very suitable to the last century 968 engine and according to the 968 Porsche owners manual the oil viscosity chart recommends 15w-50 or 20w-50 to be used in ambient temp rangers of from minus 10 deg cel ( 14F) to unlimited high ambient temps
Remember , the 968 and its oil circuit is little different to the 951( deep last century engine design ) , meaning if the oil pressure at normal & slightly above "Hot" engine oil temp ,at high RPM you are putting no 2 conrod bearing ( big end bearing ) at extreme risk , because the oil pressure is way too low at high RPM = BANG
Plus, if I was to use a 5w-40 oil vis , I would search out a oil that is high in ZDDP AW package , which is not common in a "this" century oil like a 5w-40, most 5w-40 oils have to meet this century emission protocols of low levels of ZDDP = lower oil film strength
And in relation to ZDDP & 968 / 944S/ 944S2 twin cam 16V engines over the last 10 - 15 years we have only seen ( at our independent Porsche specialist shop ) massive cam lobe wear & hydraulic lifter face wear & cam chain sprocket wear ( these are part of the cams ) if these cars were on low oil film strength oils ( mainly 5w-40 or 10w - 40 ) engine oils
Remember the 968 , like the 944S & 944S2 has very high load flat tappet design & to make matters more interesting the pointy end of the cam lobes are unusually sharp / pointy & most important of all , this area is only lubricated with NO OIL pressure at all , the cam lobes + the timing chain / sprocket are lubricated by splash only , hence the extreme importance of Oil Film Strength
How do we get high oil film strength ?
Answer }
A ) increase oil viscosity , say from 5w-40 to 20w- 50 if both oils had the same amount of ZDDP , which is nearly never the case because the last century 20w-50 vis is allowed to have higher levels of ZDDP for last century cars & the 968 is a last century car/engine
B ) Increase the levels of ZDDP( AW package)
So a 20w-50 a good ZDDP AW package is very suitable to the last century 968 engine and according to the 968 Porsche owners manual the oil viscosity chart recommends 15w-50 or 20w-50 to be used in ambient temp rangers of from minus 10 deg cel ( 14F) to unlimited high ambient temps
01-22-2015, 01:22 AM
#6
Rennlist Member
Thread Starter
Guys, thanks for the feed back on this matter. The safe bet seems to be for me to use the Mobil 1 20/50 V twin oil as I am currently using in the 951 and the 911.