Engine Oil Life and Miles Per Gallon Pids:

[WeathermanShawn]

Hey guys and Gals, I need some help. I successfully selected the Engine Oil Life Pid , and the calculated MPG Pid. I can successfully log each and have been very intrigued on how the engine oil life monitor works.

I have always used Mobil 1 synthetic oil, and I want to switch to their premium Extended life Oil, which claims a 15,000 change interval. Can I change the Oil Life Monitor to 'light" up at a different mileage interval, or is it 'hard-wired' into the PCM? Are there different calculations for different platforms.. [I.E. the Corvette ZO6 uses synthetic oil.] I know I can just reset the oil life monitor at any point to match what I want, but I am just curious to see if it possible to actually change its calculations on the change interval with my EFLive software.

Perhaps I should have started a new thread on the following question, but on the MPG Pid..has anybody have a Calculated PID that can take your total mileage and calculate an average MPG. The current one is fascinating as it appears to give you an 'instantaneous' MPG, but one that gives an average would be great.

[joecar]

Shawn,

Interesting questions...

I don't see any oil life parameters in the LS1 calibration file.


average MPG = (total miles travelled) / (total gallons used)
I don't know if the right pids are available...

or...

average MPG = integral(instantaneous MPG, t) / (elapsed time)
unfortunately the scantool does not have an integrate() function at the moment...
so you would have to do this offline in a graphing program or a spreadsheet.

[Chevy366]

In a vehicle with a DIC doesn't it do 'estimated MPG' ? In the LS1-B tunes you can set [B3501-2] .
The oil life tweak is a good idea , from what I have read the algorithm for that takes in a lot of variables to calculate the usage , duration , life etc ... http://www.cadillacforum.com/forum/archive/index.php/t-2103.html take it with a grain of salt . GM's words : http://www.gm.com/corporate/responsibility/environment/maintenance/simplified_maintenance_qa_040104.jsp

[WeathermanShawn]

Hey guys, I got the Engine Oil Life Pid (GM.EOL) validated and can currently log it. I read the original article by the developers of the GM Oil Life Monitor Algorithm (Google). It is interesting how they estimate engine oil temperature and the resulting oil life remaining. I think they start with 2.5 million crankshaft revolutions, and then calculate certain 'penalties' based on ECT on startup, revolutions, etc. It just sounds like it is engine specific. If I had a way of saying programing 5.0 million crankshaft revolutions, and calculate from there I would have it made. The Oil Life Monitor system is a pretty sophisticated algorithm.

Guys on the mileage PID, I got the MPG PID to work. Lately I have just been using the average MPG from the data 'dashboard' at the end of my log. It actually has been very accurate.

[DrkPhx]

The GM OLS is actually very good. I follow it for oil changes on my TB SS.

Here is a good article that explains the basics.

http://www.goodwrench.com/_res/pdf/OLS1.pdf

[WeathermanShawn]

The GM OLS is actually very good. I follow it for oil changes on my TB SS.

Here is a good article that explains the basics.

http://www.goodwrench.com/_res/pdf/OLS1.pdf

Yea, I agree. It is very interesting algorithm and seems to be quite accurate. I did a few logs where I did shorts trips, highway driving etc. You definitely lose the most oil life on startups with cold ECTs. If you do a stop and go, it also decreases it more rapidly.

So far, I have hit an average of ~55 statute miles per 1% of oil life usage. So, looks like I can get 5500 miles before my next oil change. But, it does not really account for those that choose the highest premium synthetic oils. And from the literature it appears that different cars have differing amount of crankshaft revolutions programmed before an oil change is required.

[WeathermanShawn]

Wolfie:

I use synthetic oil, but I have not researched it as much as you have. I do the catch can and only run up about 8000 miles per year..but I run the car hard at times..:grin:. I got the mpg pid to work. It does quite well for a trip average, but I am so used to figuring it out in my head..it is no big deal.

It appears the Engine Oil Life Monitor system is 'hard-wired' as far as how many crank revolutions (and other interesting parameters) until light-up. It actually seems like a very accurate algorithm.

Thanks for the information.

[WeathermanShawn]

Interesting on the catch can.

I ended up using the same brand you mentioned. Likewise, it does not collect that much.