Engine Oil & Last Century Porsche Road Engines , some light reading
#16
RL Community Team
Rennlist Member
Rennlist Member
Would you gents consider 5w-50 too thin? I'm running a high quality oil (Liqui Moly) year around and I always get 3.5 bar oil pressure at warm idle. Temperatures range from -20 to 40 Celsius at the extremes here.
#18
Let's not allow pesky facts to get in the way :-)
I run Rotella T6 5W40 in my 968 (and 928) and oil pressure is no different than when running 20W50 - winter or summer.
For the curious, head over to the 928 forum to read a thread with the same subject.
Hugo
I run Rotella T6 5W40 in my 968 (and 928) and oil pressure is no different than when running 20W50 - winter or summer.
For the curious, head over to the 928 forum to read a thread with the same subject.
Hugo
#19
Drifting
Thread Starter
Hi Hugo , it is impossible to get the same engine oil pressure at the same oil temp from a 5w-40 and a 20w-50 , that's why wee see in hot weather 928 ,928S, 928 S4's , 928Gt's , 928GTS's , 944 ( all versions ) , air / oil cooled 911variants ( all last century Porsche's) that are on a 5w-40 ,their oil pressure Warning Light is glowing at idle ( Not Enough Oil Pressure ) when the oil temp is above 100 deg cel or so ( Basic Physics ) & in this low oil pressure state the engine will NOT generate enough oil pressure at high RPM to fully protect the con-rod bearings ( big end bearings as we call them ).
The other thing you may not know ( understandable ) is that on you're 928 , the 928 in the dash oil pressure gauge only reads up to 5 Bar , but the 928 engine ( all versions ) the oil pressure relief valve opens at 8 Bar , so the 928 should have a 0-10 bar oil pressure gauge just like the Porsche 931 had and the early 911 series did ( 0 - 10 Bar gauge ) , so you are getting an incomplete reading when you see the oil pressure gauge "Pegged " as people say at 5 Bar , the gauge is incomplete & gives you the wrong impression .
All very very very very simple physics , this is not rocket science
Regards
Bruce B
The other thing you may not know ( understandable ) is that on you're 928 , the 928 in the dash oil pressure gauge only reads up to 5 Bar , but the 928 engine ( all versions ) the oil pressure relief valve opens at 8 Bar , so the 928 should have a 0-10 bar oil pressure gauge just like the Porsche 931 had and the early 911 series did ( 0 - 10 Bar gauge ) , so you are getting an incomplete reading when you see the oil pressure gauge "Pegged " as people say at 5 Bar , the gauge is incomplete & gives you the wrong impression .
All very very very very simple physics , this is not rocket science
Regards
Bruce B
Last edited by JET951; 01-11-2018 at 05:51 AM.
#22
924srr27L's 205bhp 2.7 8v used running in oil for 50 miles, then 20W50 Classic (1950's low deterent, high ZDDP) Mineral MOTUL Oil for the next 3000 miles
Then since then Joe Gibbs XP5 Semi-Syth 20W50 Racing Oil every 1000 miles, (And soon to be after every 2 hour Endurance Race for this year)
The Oil pressure is very good and the consumption very low.......
R
Then since then Joe Gibbs XP5 Semi-Syth 20W50 Racing Oil every 1000 miles, (And soon to be after every 2 hour Endurance Race for this year)
The Oil pressure is very good and the consumption very low.......
R
#23
Nordschleife Master
Entered "diesel oil in motorcy..." and it auto filled to "Rotella diesel oil in motorcycle" and gave this:
https://www.google.com/search?q=rote...hrome&ie=UTF-8
#25
Burning Brakes
#26
Drifting
Thread Starter
Hi Wisconsin Joe , thanks for showing me the interesting array of what people choose to use, in this case using diesel oils in motorcycles that are not diesel , I had never heard of it before , in regards the motorbike /s that you own or have owned , what would be the overage price difference between the diesel oil & the dedicated motorbike engine oil in doing one oil change ?
And in you're opinion ( in you're state ) or USA as a whole , what percentage would you think qualified motorcycle mechanics recommend not using proper motorcycle oil & instead recommend using diesel oil in a non diesel motorcycle engine
And in you're opinion ( in you're state ) or USA as a whole , what percentage would you think qualified motorcycle mechanics recommend not using proper motorcycle oil & instead recommend using diesel oil in a non diesel motorcycle engine
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Dwizle (04-01-2021)
#27
Nordschleife Master
Well, price is about 4x for the synthetic vs diesel. 1 quart of the snyth M/C stuff goes $10 - $12, and I can get a full gallon from a friend who runs a shop for that much. My M/C takes 4 quarts on a change.
But, cost really isn't the driving factor. I change the oil once a year and the cost of an engine (or even a rebuild) makes the $35-$40 difference for a yearly change minor.
I like the detergent properties and the somewhat heavier weight. The narrower range (15-40) is also supposed to be more stable. My understanding is that the wider the range (say 0-40 or 5-40) the sooner the breakdown. For example, the M1 0-40 recommended for Cayennes will "shear down" to 30 weight within 5k or 6k miles. This has been discussed to death over in the Cayenne forum.
I have no clue what percentage of mechanics suggest doing what I do. I don't even suggest it myself (I'm not an expert). I suggest other people do their own research and make their own choices.
i have also experienced "qualified mechanics" who have no clue about stuff that doesn't involve "nuts and bolts" wrenching. Stuff like fuel additives, using ethanol gasoline, and...
Oil choices.
But, cost really isn't the driving factor. I change the oil once a year and the cost of an engine (or even a rebuild) makes the $35-$40 difference for a yearly change minor.
I like the detergent properties and the somewhat heavier weight. The narrower range (15-40) is also supposed to be more stable. My understanding is that the wider the range (say 0-40 or 5-40) the sooner the breakdown. For example, the M1 0-40 recommended for Cayennes will "shear down" to 30 weight within 5k or 6k miles. This has been discussed to death over in the Cayenne forum.
I have no clue what percentage of mechanics suggest doing what I do. I don't even suggest it myself (I'm not an expert). I suggest other people do their own research and make their own choices.
i have also experienced "qualified mechanics" who have no clue about stuff that doesn't involve "nuts and bolts" wrenching. Stuff like fuel additives, using ethanol gasoline, and...
Oil choices.
#28
Rennlist Member
I've done it more times than i can count, as my car was driven 150miles into the mountains of colorado regularly and cold soaked overnight at temps as low as -25f at an altitude of 10,000ft. With 0w40 in the pan it always started the next morning. It was a slow start on the super cold days, but she fired up and was outputting heat in the cabin pretty quickly. These cars are fantastic in the snow with proper tires. That said, i'm 15w-50 the rest of the year, 0-40 is waaaay to thin for warm/hot days.
#29
Unfortunately that is not commonly available here. My goto "get anywhere" is 0-40 and 15-50 m1.
#30
Burning Brakes
Bruce B - nice info. I'm running a standard (with sump baffled) 944 S2 race car here in NZ. The other guys all seem to use the 5W-50 mobil 1 but I believe thats not really good and have made the switch to Penrite Racing 15W-50 for zinc levels more than anything else (as the hot vis is still the same).
Our ambients are around the 15-25C range and my car seems to keep its cool very well on race days compared to some of the other 944 guys.
Thoughts on my selection or penrite in general?
Penrites own selector even gives you the "preferred" oil as 5W-40!!
Cheers
Our ambients are around the 15-25C range and my car seems to keep its cool very well on race days compared to some of the other 944 guys.
Thoughts on my selection or penrite in general?
Penrites own selector even gives you the "preferred" oil as 5W-40!!
Cheers