Coquihalla highway 120 kms. That means you can take a run at the 8% grades at 135.
Any semi truck drivers? Curious about OCI.
- Thread starter JamusMcFamus
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OCI should be based on fuel used and hours not miles.
OCI will depend on engine and its emissions strat. Euro based engines focus more on DEF for nox reduction so less egr, American generally favors EGR to control nox over DEF so you will want to reduce OCI on Cummins based engines. (PX series included as they are just rebranded cummins)
The euro based engines generally have centrifuge style bypass oil filters from the factory (Pacc, DD)
I run a 14k on a 6nz cat, 20k on our isx15 and 7k on a ISX12.
All are used in extreme service, all have custom programming in the ecm.
They know the engines will make the 500k warranty at that OCI. Fleets want lowest cost of upkeep.
This is extremely evident in the DD series. Running extreme tall gears and 900-1000rpm cruise.
Those same engines at 500k have literal soot in the head when the VC is off and the bottom end is shot at 600k from the life of lugging,
OCI will depend on engine and its emissions strat. Euro based engines focus more on DEF for nox reduction so less egr, American generally favors EGR to control nox over DEF so you will want to reduce OCI on Cummins based engines. (PX series included as they are just rebranded cummins)
The euro based engines generally have centrifuge style bypass oil filters from the factory (Pacc, DD)
I run a 14k on a 6nz cat, 20k on our isx15 and 7k on a ISX12.
All are used in extreme service, all have custom programming in the ecm.
They know the engines will make the 500k warranty at that OCI. Fleets want lowest cost of upkeep.
This is extremely evident in the DD series. Running extreme tall gears and 900-1000rpm cruise.
Those same engines at 500k have literal soot in the head when the VC is off and the bottom end is shot at 600k from the life of lugging,
There are several states that post 75-80 MPH limits in certain areas Texas, Oklahoma, Montana, Nevada ... some restrict Trucks to lower speeds though...
Last time I was on IH10 west of Houston 75 would get you run over...
Last time I was on IH10 west of Houston 75 would get you run over...
I have seen this
Would like to see pictures of those, had no idea the bottom ends don't last in these engines.
DD series and Cummins suffer the worse.
DD it hammers the big ends out.
Cummins it frets the mid stops on the liners and they drop.
Im not talking about S60 or older.engines - im talking about GHG17 and newer stuff. They run 19+:1 compression, peak torque down at 1k, and tall gears to get driveline speeds down.
X15 cummins runs 19.3:1 compression with IVAs to bleed cyl pressure under full load, EGR to control burn and pressures etc.
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Overall i would say low percentage. I deal with trucks that generally haul 140-160k or trucks just sold off by fleets.
DD anything GHG17 or newer 600-700 is end of life i would say 25-30% ive handled are done.
Cummins - it has been an issue since the isx first came out with the mid stop liners. its becoming more prevalent with the lugging and the higher compression ratios. at 1650tq they will still generally make 800k. 2050 head is usually off around 500-600k because of liners
Wow, that seems like a short life expectancy. Down speeding saves fuel and slowly beats the engine to death. Now I understand why so many fleets sell at 500,000 miles.
Pull the cover on once and you will understand. Hollow cam, underbuilt valvetrain, injectors that last 250k etc. They are OM series from Mercedes.
Would you be willing to take some pictures for us?
Certainly however I don't turn wrench much anymore so might take a bit. I do more on the Calibration side.
I see my fair share of weird failures and engines abused well outside the oe design so I can always post interesting stuff.
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A few years ago a day cab driver for large freight hauler said their tractors used the lost oil method where a very small amount of crankcase oil was pumped to the fuel tanks and the drivers would add oil accordingly as needed. Don`t remember what the filter change interval was but the engines did not suffer.
What is the "lost oil method"?
4WD
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That’s interesting - I have a fair amount of 0W20 left and concerned with GDI dilution from many short trips in a 9 month OCI … so use the Fumoto to swap a quart around 40% OLM … Quick and easy … Check under the hood at that time …
As told to me a small amount of engine oil is pumped into the fuel tank which in a diesel burns readily. When I get a chance I`ll ask this retired driver how much oil is lost over how many miles.
When I was OTR, we did 25k mile OCIs. We leased the tractors from the company and were considered O/O, so it was my intention to keep the truck running great for as long as possible with minimal downtime. I used M1 Delvac full syth, not cheap at the time.
That DD15 burned about a gallon per OCI, it had what I considered too much blowby. Ran plenty strong and averaged over 6mpgs hauling mostly heavy loads (paper rolls, water, canned goods).
That DD15 burned about a gallon per OCI, it had what I considered too much blowby. Ran plenty strong and averaged over 6mpgs hauling mostly heavy loads (paper rolls, water, canned goods).
In general, OCIs for heavy trucks are less dependent on mileage, and more so on engine hours or fuel consumed. This is especially true for severe-service tractors and trucks, which (unlike line-haul tractors) tend to operate over a wider variety of vehicle speeds and variable load conditions, generally with a much lower average speed and often times lots of idle time or PTO operation which mileage alone won't indicate.
I have driven for the same company for 35 years. My company has for the last 25 years been doing oil fleet testing for Mobil Delvac 1. With this oil we were running 80,000 mile oil change intervals with samples taken every 12,000 miles along with filter changes. A few years back they changed to 60,000 mile changes. The company has well over 700 trucks with no out of ordinary oil related problems. The most common reason for an early change I've seen is excessive soot contamination from the air filter not flowing properly which forces an early oil change.
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