Hours vs. Mileage OCI

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Originally Posted By: surfstar
Ultragauge can keep a trip meter of gallons consumed also.


My C3 tracks gallons burned,miles/kms and hours operated.

What does everyone think about a 6.0 Chev engine. How many gallons of fuel burned would necessitate oil change.
 
I work on forklifts and heavy equipment. The Volkswagon TDI in our 7,000 lindes call for 500 hours on syn and 250 on dino. C7 IN our loader gets 200 hour changes. Cat lifts with diesels get 150-200 hours. Oil samples come back good except for lindes that have intake side problems. Due to our dusty conditions, all oils from our 250 gallon bulk tanks go through filters.

That said, i go 200 hrs on my dodge cummins with 208,000 miles and mileage on my other 3 cars as mostly smooth running freeway. If i lived in LA with that traffic, i would install an hour meter.

I have only seen fuel consumption used in relation to hours and excessive oil usage.
 
I was going to post the same question. Every internal combustion engine on the planet does oil changes based on hours---except passenger cars and light trucks. Makes no sense. The EPA and National Hwy Council claims an avg speed of 48.6 mph for vehicles doing hwy type driving, and 21 doing "city". So it makes sense converting to hours.

As an example, I'll use my Hyundai. It says normal service is 7500 miles ....severe is 3750. 7500/50 = 150hrs. 3750/25=150hrs.
Average or 21 would= 3150 miles. This is assuming conventional oil.

Now let's look at oil claims. As an example, Mobil 1 claims 10,000 miles. At hwy speed that would = 200 hr oil life. So at an avg speed of 25 it would be 5000 miles. or say 37 would =7400 miles.

So you can see where this is going. I think it would be very useful if OEM's and oil blenders offered hours on running time components vs just miles. Miles for tire rotation is fine. They aren't rolling while you are sitting traffic idling, but your engine is doing 700 rpm all that time.

Something to think about.
 
For a car I don't really get the point, but for a truck doing a lot of stationary operation hours can be critical.

Its not unusual for say a truck to run 20 miles in the morning than if its say spray foaming use the motor as a generator for 6-8, than 20 back to the shop.

Having said that typically these trucks have OLM's that take this into account, like GM.

Most manufactures figure cars are driven. The only time I would be concerned with hours on a car if it was say a service or police car, where the motor will be running all shift regardless of miles traveled.
 
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Having run fleet trucks with engine driven PTO cleaning equipment since the 70's I have a bit of experience in this.

In the old daze we routinely tracked fuel consumption. This remains a VERY accurate way to change your oil.

At one point we used hour meters to allow for a combined calculation of mileage plus stationary hours running. The Ford number above is an extremely accurate one, as we used 35 mph/hr for almost a decade.

Nowadays our all GM fleet has the OLM, which takes into account every single turn of the crankshaft. No guessing anymore, just change when the computer tells you. Typically around 4500 miles or so...
 
Time, mileage, or gallons consumed...depends on driving style, oil used, and engine(state of tune, MPG, sump capacity, filtration, oil consumption).

You can help pick your parameters using UOA with tbn.
 
Only drawback to fuel consumption is the tracking. Unless a meter is installed or you have good operators who follow directions, miles and hours both advance autonomously.....

ok i've been drawn in. Oils, engines and filters (except the current failures) are really good products. Foolow the manufactures recomended intervals and drive the wheels off. Fix the wheels and drive it some more. People are getting huge miles out of their vehicles.

regards,
Mike
 
Seems to me that a function of hours and fuel consumption is required. Drive light, easy on engine. Drive the same engine hard and it burns more gas, and probably needs an oil change sooner. Problem is, w/o some way to measure actual true wear and tear on a fleet of engines... one is guessing.

I'd be tempted to put in an hour meter on my cars, but w/o massive amounts of data it would be no better the odometer I think; I would not have any clue how to use fuel burned plus hours to come up with when I ought to change.
 
How often do NY City taxis change their oil? Lots of idling. Seems like Consumer Reports tested this many years back and they were checking results after 3000 and 6000 mile OCIs. 3000 miles in the city with lots of idling equals a lot of hours.
 
Let's take a look at a hypothetical situation.

You are looking for a good used car. You find 2 identical cars with 50,000 miles each. They both look and run great. But what you don't know is how they were driven. An hour meter would help with that.

Car #1 driven mostly short city trips, averaged 22 MPH.

Car #2 driven some short but mostly hwy averaged 38 MPH.

Car #1 = 2272 hrs on the drivetrain.

Car #2 = 1316 hrs on the drivetrain.

If all other factors were equal, which would you buy?

And which would you be willing to pay a little more?
 
Not surprisingly, if driving setting remains consistent mileage, hours or gallons, either can be used as an OCI guide. Mileage, of course, is the easiest to track.

I ran some numbers on the data I have, and given the engines are still breaking-in, decrease in wear metals using ppm/mile, ppm/hour and ppm/gallon methods are virtually identical. For Wrangler I did some mods (2" lift, 32"->33" & wider tires, heavier aftermarket bumpers) between the OCIs. After that mpg dropped by almost 3 miles/gallon. Hence, decrease in wear metals from one OCI to next is greater using gallons method because more gallons are used.

Here are the figures Mileage vs Hours vs Gallons Analysis. Earlier I stated I ran 201hrs on Amsoil XL 5w/30 and got to TBN 1.8. My memory served me wrong, it was 154hrs.

QqdHkP5.jpg
 
I read something somewhere (possibly here) about the programming of the oil-life monitors newer vehicles have.

Apparently they were initially quite complicated taking into account a number of factors until someone realized it could really be calculated quite accurately by fuel burned.
 
Bump: I have an entire thread over on Tacomaworld about this, let me know what you all think. Rather than post it all here, I'll just link you to it Tacomaworld UG Data. I'm looking forward to hearing more thoughts on how engine hours relate to miles and OCIs.

The following is my latest post on the previously linked thread:
Originally Posted By: "07 sport 4x4, post: 16571480, member: 48165"
I found this today, Dodge challenger maintenance recommendations for the 3.6 and 5.7 liter engines. The 3.6 holds 6 quarts of 5w20 and the 5.7 holds 7 quarts of 5w20. Dodge recommends 10,000 miles, 350 hours or 12 months, whichever occurs first.
10,000 miles divided by 350 hours would give you an average speed of 28.57 mph.

(1/2 of that recommendation, which is what Toyota recommends for the 4.0 Tacoma would be 5,000 miles, 175 hours, or 6 months...just a thought.)

Then they go on to say that if your vehicle is operated in severe conditions (off road or dusty conditions) you should change the oil every 4,000 miles.
That would give you an estimate of about 140 hours per OCI under severe service, assuming an average speed of 28.57 as suggested earlier. I guess the question is whether or not the 350 hour recommendation applies here?

4,000/350=11.43 Avg MPH, if the 350 hour recommendation applies here.

Let's pretend for a minute that I own one of these vehicles and use it in the same manner as I use my truck. On my last OCI I averaged 13.8 MPH, so according to Dodge I would have needed to change my oil at 4000 miles. 4,000/13.8=289.86 hours. This would put me well under the 350 hour recommendation (the question remains, does the hour recommendation change under severe service?).

On the flip side, if I went 5,000 miles(ignoring the 6 month interval) as Toyota states you should (for my Tacoma), I would have been at 362 hours of runtime, Assuming I had gone by miles instead of time. On my last OCI I changed my oil at the 6 month mark(Toyota requires 5k/6mo for the Tacoma), which was a little over 185 hours, but only 2,550 miles.

If I was following a 10K/12 month interval like a lot of new vehicles do, I would be nearing 400 hours of run time by the end of the year/OCI, based on my current driving habits.


The full manual can be found here: 2017 Dodge Challenger

Original post is on Tacomaworld
 
Originally Posted By: Merkava_4
What you guys do with the oil if it was at:
- 2000 miles
- one year
- OLM @ 50%

Most manufacturers require at least one OCI per year regardless of OLM percentage or mileage.
What kind/year of vehicle? GM added the 1 year factor into their OLM for the 2013 and newer vehicles, IIRC.
 
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My vehicle has an hour meter on it. I trust the OLM but use a full synthetic motor oil as an extra measure of protection and because of cold temperatures.
 
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