Thicker oil made a noticeable difference.
02-12-2011, 10:27 PM
#1
Rennlist Member
Thread Starter
Thicker oil made a noticeable difference.
I drained my oil this evening even though it has only 1k miles on it because I wanted to switch from Mobil 1 10W-30 to 10W-40 as recommended by several forum members. I had some issues last time I changed the oil as it appeared to have metal particles in it. Also I haven't been happy with the oil pressure readings I was getting on the gauge (gauge accuracy has yet to be determined but that is another story). It is also worth noting that the oil which I just drained out did not appear shiny as it did during the previous oil change, but then again this oil is only 1k miles and 2 months old. At least I know there isn't a huge internal problem if one exists at all.
The gauge used to read about 2.5 to bar at idle, but sometimes it would drop to 2.0 or slightly lower when the engine got really warm, even though the ambient temp has been in the 20s most of the time. When giving it throttle (engine up to temp) the oil pressure would not always reach 5bar at 2k rpms. With the thicker oil it now reads 2.5-3.0 bar at idle, and quickly climbs to 5bar as I give it gas.
I am planning on getting an oil pressure tester so I can get more accurate readings as well as assess gauge accuracy. My question is whether or not my current oil pressure readings are where they should be. IIRC 2.5-3bar at idle is good, and the WSM states that at 2k there should be 5bar. AllData says that there should be 5bar at 4k rpms. Is it acceptable to have 5bar at engine speeds lower than 2k?
The gauge used to read about 2.5 to bar at idle, but sometimes it would drop to 2.0 or slightly lower when the engine got really warm, even though the ambient temp has been in the 20s most of the time. When giving it throttle (engine up to temp) the oil pressure would not always reach 5bar at 2k rpms. With the thicker oil it now reads 2.5-3.0 bar at idle, and quickly climbs to 5bar as I give it gas.
I am planning on getting an oil pressure tester so I can get more accurate readings as well as assess gauge accuracy. My question is whether or not my current oil pressure readings are where they should be. IIRC 2.5-3bar at idle is good, and the WSM states that at 2k there should be 5bar. AllData says that there should be 5bar at 4k rpms. Is it acceptable to have 5bar at engine speeds lower than 2k?
02-12-2011, 10:44 PM
#3
Drifting
I would suggest you read the owners manual for your car. It discusses both the oil pressure gage vs RPM, and the recommended oil viscosity classes by climate temperature range.
02-12-2011, 10:54 PM
#5
Three Wheelin'
If it gets Hot down where you live in summers, use 20W50. Temperature here gets in to the 90+ range in the summers, and some have said their oil light came on with 15W50, when they switched back to 20W50 the problem was gone. They were using Royal Purple.
Trending Topics
02-12-2011, 11:03 PM
#8
02-12-2011, 11:08 PM
#9
Supercharged
Rennlist Member
Rennlist Member
Join Date: May 2002
Location: Back in Michigan - Full time!
Posts: 18,925
Likes: 0
Received 59 Likes
on
33 Posts
One point... the Mobil1 10-40 you put in your car is a step above the 10-30 you had, but you still do not have enough ZDDP in my opinion. Our flat tappet engines need this for proper lubrication.
Check this table out.
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
Personally, I look for 1200ppm or higher. There are a few other oils int he same viscosity range with the proper level of ZDDP. Brad Penn, AMSOIL, etc.
Do your own research.
Check this table out.
http://www.mobiloil.com/USA-English/...duct_Guide.pdf
Personally, I look for 1200ppm or higher. There are a few other oils int he same viscosity range with the proper level of ZDDP. Brad Penn, AMSOIL, etc.
Do your own research.
02-12-2011, 11:17 PM
#10
Former Sponsor
I feel like I'm trapped in "Groundhog Day."
Can't we have a place to go where people can read the threads that have been already done about oil thickness? I don't even have to read the answers from the people that post them...I already know exactly what they are going to say.
It's almost like Deja Vu on a bad acid trip....not that I'd know what that was.
Can't we have a place to go where people can read the threads that have been already done about oil thickness? I don't even have to read the answers from the people that post them...I already know exactly what they are going to say.
It's almost like Deja Vu on a bad acid trip....not that I'd know what that was.
02-12-2011, 11:19 PM
#11
I feel like I'm trapped in "Groundhog Day."
Can't we have a place to go where people can read the threads that have been already done about oil thickness? I don't even have to read the answers from the people that post them...I already know exactly what they are going to say.
It's almost like Deja Vu on a bad acid trip....not that I'd know what that was.
Can't we have a place to go where people can read the threads that have been already done about oil thickness? I don't even have to read the answers from the people that post them...I already know exactly what they are going to say.
It's almost like Deja Vu on a bad acid trip....not that I'd know what that was.
02-12-2011, 11:23 PM
#13
Former Sponsor
I'm not picking on the guy that posted the thread...everyone has questions...and I encourage people to ask them...it just seems like this should be up there in the very top section:
"Before you waste your money buying oil at Walmart...read this."
"Before you waste your money buying oil at Walmart...read this."
02-12-2011, 11:24 PM
#14
Race Car
My turn... unless you live in a place where the temps get below ~10 deg F regularly and you are still driving the car, you should be using 15W-50 oil. There really is no reason to use anything thinner in a 928. But hey, it's your bearings...
Dan
'91 928GT S/C
475hp/460lb.ft
Dan
'91 928GT S/C
475hp/460lb.ft