Oil Life Algorithm
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 1,159
Likes: 0
From: Columbia MO
Oil Life Algorithm
A few years ago Evil Twin posted a really detailed explanation of how the OLA calculates oil life. I searched the current AND the archived posts but can't seem to find it. Did anyone perchance save a copy of it?
A co-worker swears his mechanic told him the his Cobalt has an oil viscosity sensor driving his oil life meter. I explained that was BS, and told him I'd try to find the parameters used. Although I'm sure his Cobalt doesn't have a 15K mile baseline, and I know he's not running a synthetic.
Help me out guys.
A co-worker swears his mechanic told him the his Cobalt has an oil viscosity sensor driving his oil life meter. I explained that was BS, and told him I'd try to find the parameters used. Although I'm sure his Cobalt doesn't have a 15K mile baseline, and I know he's not running a synthetic.
Help me out guys.
Instructor
Joined: Oct 2006
Posts: 234
Likes: 0
From: Phila Pa
Here's his response to the original post about how the system works
Here is how the OLM system works..
Mileage has little to do with how oil is monitored, here is the idea:
Car 1:
If you drive 90% of the time on the highway lets say 1500 rpm an hour.
you engine sees 90,000 revolutions in that hour and you drive 60 miles.
Car 2:
If you drive around town, profiling with 90% of your driving in 1st, 2nd, and 3rd gear, taking 4,000 rpm on average. That's 240,000 revolutions of the engine in 1 hour and you only drive 30 miles.
Taking this out to 3 months , 90 days:
Car#1 3,600,000 rpms and 5400 miles
Car#2 21,600,00 rpms and 2700 miles
This represents 1 hour of driving a day for 90 days.
Car #2 sees 6 times the engine duty of car #1 and Only half the mileage
So you can see that mileage can be very misleading.....
Here is how the OLM system works..
Mileage has little to do with how oil is monitored, here is the idea:
Car 1:
If you drive 90% of the time on the highway lets say 1500 rpm an hour.
you engine sees 90,000 revolutions in that hour and you drive 60 miles.
Car 2:
If you drive around town, profiling with 90% of your driving in 1st, 2nd, and 3rd gear, taking 4,000 rpm on average. That's 240,000 revolutions of the engine in 1 hour and you only drive 30 miles.
Taking this out to 3 months , 90 days:
Car#1 3,600,000 rpms and 5400 miles
Car#2 21,600,00 rpms and 2700 miles
This represents 1 hour of driving a day for 90 days.
Car #2 sees 6 times the engine duty of car #1 and Only half the mileage
So you can see that mileage can be very misleading.....
Race Director
Joined: Jan 2006
Posts: 10,554
Likes: 33
From: Not on either liberal coast.
...and because there's so many variables about how an owner drives their car compared to someone else, that's why GM suggests the oil change at one year regardless of the DIC oil life % remaining. Otherwise, some owners would be changing their oil at five year intervals.
I personally think that with quality synthetic oil/filter, the one year could be extended with a simple oil analysis...
I personally think that with quality synthetic oil/filter, the one year could be extended with a simple oil analysis...
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 1,159
Likes: 0
From: Columbia MO
Thanks guys, I know all that. But he listed a lot of specifics that subtract from your baseline.
Cold Starts
Orperating Temp vs. RPMs
Sustained high RPMs
etc.
It's not life or death, so if you don't have it, don't sweat it.
Thanks guys.
BTW: I thought about that MagRed, but it's not a big enough deal to bother him. I don't even particularly like this co-worker.
Cold Starts
Orperating Temp vs. RPMs
Sustained high RPMs
etc.
It's not life or death, so if you don't have it, don't sweat it.
Thanks guys.
BTW: I thought about that MagRed, but it's not a big enough deal to bother him. I don't even particularly like this co-worker.
Burning Brakes
Joined: Dec 2003
Posts: 1,066
Likes: 9
From: Eddy Texas
Found the thread you are referencing, but the links in it are no longer good(Jan '06). I remember that post, but I can't find a similar description on the web.
http://forums.corvetteforum.com/show....php?t=1282880
http://forums.corvetteforum.com/show....php?t=1282880
PM ET..he's around somewhere, I think he was on here this morning...
