Pondering what oil to use in my Pontiac G8-GT

[LS2JSTS]

Originally Posted By: Bill in Utah
Originally Posted By: LS2JSTS
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=130036#Post130036


That's it! Had quite a few PMs with the guy before he "departed"..


Who can blame him for leaving. He came on this board with valuable insider information and ends up catching flack for Dex Cool, bean counters and the Pinto.

 

[Bill in Utah]

Originally Posted By: 3311

Yes, The other factors mentioned all affect engine temperature so why factor them independently. Not trying to argue, it is only my opinion based on my limited readings on the subject.


The system factors them independently because to the engine and oil there is a lot of difference between just temps and RPM.

So if the system looks at x number of RPM (lets pretend 2000 RPM times 60 mins per hour = 120k per hour times 50 MPH would be 100 hours to make 5000 miles. So 120000 times 100 hours = 12 million revs) and at x number of revs the light goes on. So if the vehicle idles at 1000 RPM (I'm trying to make it simple) the light would go on at 500 hours...

I think the oil and engine suffer a lot more at idling then driving down the road @ 50 MPH. Yet if the system only measured RPMs to figure out when the light comes on it would come on much sooner with the driving then idling (which nails the oil much worst then most anything else)

Big difference with load, temps, what temp the engine is when it is driven and how it is driven.

Bottom line, A system that SHOULD be in every vehicle. GM did an EXCELLENT job with it and if anything should be MANDATORY in an vehicle it should be an OLM. (instead of idiot things like TPMS

and such)

 

[3311]

Originally Posted By: Bill in Utah
Originally Posted By: 3311

Yes, The other factors mentioned all affect engine temperature so why factor them independently. Not trying to argue, it is only my opinion based on my limited readings on the subject.


The system factors them independently because to the engine and oil there is a lot of difference between just temps and RPM.

So if the system looks at x number of RPM (lets pretend 2000 RPM times 60 mins per hour = 120k per hour times 50 MPH would be 100 hours to make 5000 miles. So 120000 times 100 hours = 12 million revs) and at x number of revs the light goes on. So if the vehicle idles at 1000 RPM (I'm trying to make it simple) the light would go on at 500 hours...

I think the oil and engine suffer a lot more at idling then driving down the road @ 50 MPH. Yet if the system only measured RPMs to figure out when the light comes on it would come on much sooner with the driving then idling (which nails the oil much worst then most anything else)

Big difference with load, temps, what temp the engine is when it is driven and how it is driven.

Bottom line, A system that SHOULD be in every vehicle. GM did an EXCELLENT job with it and if anything should be MANDATORY in an vehicle it should be an OLM. (instead of idiot things like TPMS

and such)


I would guess that it would not factor them interdependently. It would work this way imo, i would take accumulated rpm and factor them (constantly) against the engine temperature.
Let's say at start up the engine temp is 20°f then it would multiply those accumulated rpm by a factor .20. If vehicle is driving down the road (or idling in traffic) and is at normal operating temperature then those accumulated rpm would be multiplied by a factor 1.0. If your towing a boat or hauling a heavy load in here beautiful Fla and your engine is at 220° then it would multiply those accumulated rpm by .8. My multipliers are only guestimates.

I believe only operating temperature and rpm are accounted for.

I have certainly not read any of the sae papers and my my explanation/guesstimation of the algorithm may seem overly simplistic but I firmly believe in the theory of Occams Razor.

I do wholeheartedly agree that the Gm OLM is a fantastic system and should be used if your vehicle is so equipped. I have typically run it out to 200% with a quality synthetic( M1 5w30 without uoa's) and my 04 2500hd is in excellent shape.
Now if I can get the Delo I switched to do that( with the help of a uoa's) I'll be pretty happy.
Have a nice weekend all!

 

[HTSS_TR]

Originally Posted By: Bill in Utah

Bottom line, A system that SHOULD be in every vehicle. GM did an EXCELLENT job with it and if anything should be MANDATORY in an vehicle it should be an OLM. (instead of idiot things like TPMS

and such)

+1000

I don't have TPMS in any of my old cars (newest is 2004 S2000), I have many cars before the current 3 cars and never had any problem with low tire pressure in any of them. If there is one thing I like to not included in any car is TPMS, I hate this dumb feature.

 

[Bill in Utah]

Originally Posted By: HTSS_TR
Originally Posted By: Bill in Utah

Bottom line, A system that SHOULD be in every vehicle. GM did an EXCELLENT job with it and if anything should be MANDATORY in an vehicle it should be an OLM. (instead of idiot things like TPMS

and such)

+1000

I don't have TPMS in any of my old cars (newest is 2004 S2000), I have many cars before the current 3 cars and never had any problem with low tire pressure in any of them. If there is one thing I like to not included in any car is TPMS, I hate this dumb feature.


We have it on our 2006 and newer vehicles at work and EVERYONE of them have the IDIOT light on. We just ignore them due to the cost of repairing the sensors and right away they fail again.

POOR system.

Bill

 

[SuperEd73]

Hello again,

Well I figured I'd take a look to see what I had sitting in my oil stash. It's not very robust as compared to many members on the board. I did find 10 quarts of Valvoline SynPower 5W-30. I'm thinking I probably bought the oil when I was experimenting with different oils for my Subie WRX when I had it. That was before I figured out that the Subie would shred 5W-30s into the 20 weight range so I ended up switching to RTS 5W-40 until I sold it when I bought the G8. I might just use that or if I come across a good sale pick up a couple of jugs. I was thinking the 400 miles or so I put on the car yesterday (trip to upstate NY) would get me down to the "Change Oil Soon" OLM life reading but not yet! So, I still have time.

Also regarding the TPMS. My G8 has that system as well. I do find it a bit odd that when I check the tire pressures with my electronic gauge, Both rear tires are at 38psi but the display on the car shows one at 37psi and the other at 39psi. I suppose it's a good failsafe but I tend to be more proactive with regards to make sure things like tire pressures are checked pretty often. Of course maybe it's not a good failsafe in the case of Bill In Utah with the idiot light coming on way too often.

Ed B.

 

[WANG]

G8 GT UOA

^That was my 1st UOA on this car. For my location and typical duty cycle, I won't be going beyond the OLM.

 

[Durango]

SuperEd73,

That stash of Valvloine "SynPower" you have is a good oil and I wouldn't hesitate in using it at all. How it compares to my standard Mobil 1 I can't say but if it sheds it's 30 down to a 20 weight then I figure it's good foor your fuel mileage and at the same time protectingyou well.

Like yours my electronic tire pressure warning idicator is not perfect either sometimes it's actual pressure is always a couple pounds higher than my tire guage says. I don't worry about it much as I check my tires every month and know it's reading.

Ohwell have a great weekend!! Saturday is nice and warm just like my old summers when I was a kid again.

Durango