correct. I wish there was a total engine hours clock that didn't reset.

I watch my ave mileage as an early indicator of engine issues. I also compare my engine hours to mileage per tank.

The combination of mileage and engine hours is much better data for maintenance intervals (like oil changes) than mileage alone.

 

So, suppose you didn't have a working or existing odometer... what would be the interval change based on engine hours alone?

 

Well, by itself, the one parameter doesn't tell enough of the story. Much like mileage alone. The combination of mileage and engine hours gives a better indication. And adding more parameters is better still. (hence the oil life indicators on most new vehicles)

Think of 100 engine hours in a vehicle.

Consider that in combination with 1,000 miles driven or 6,000 miles driven.

That's 10 miles per engine hour verses 60 miles per engine hour. The first would have to be some serious stop and go traffic driving and the other some serious open road highway cruising.

My average is right around 40 miles per engine hour. I change my (mobil 1) oil between 5,000 and 5,500. I never see the Oil Change Light (well, once I forgot to reset the OCI and it came on after about 500 miles).

Here's another reason mileage alone is a bad indicator. (or any parameter alone)

Consider this rough example (lifted from a BITOG post, link below)

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 21,600,000 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

http://www.bobistheoilguy.com/forums...1735142&page=1

 

I believe once you get enough time built back up on the timer it will switch back to hours.

 

If this hour meter was to be used for anything important it would not be resettable. I see no use for it at all, just a gimmick IMO.

 

I agree, and for the most part think the same thing about the trip odometer. I suppose its nice for the once a year time you may want it, but beyond that its another 500 of my bucks going to Chrysler. *shrug*

 

I like the trip odometer. I use the #1 odometer to track my fuel mileage every time I fill up and #2 for trips I take out of town, just to see the total mileage I drove.

 

when I ordered my JK built, I had the trip odometer option deleted and spent the $500 on something useful: the low-windshield-washer-fluid warning light.