# OCI , how many hours of running?

#### dustyjoe1

I've been thinking about changing my old habits from doing OCI in thousands of miles to hours. A thread a while back suggested it was better doing it that way, and I tend to agree. Question is, How many hours is the accepted standard? Someone suggested 40 hours on off the shelf synthetic (g3). Does that sound reasonable. I currently use 5w20 motorcraft and havoline in my ford trucks. Thanks in advance.

#### zoomzoom

I think that is way conservative..Let's say you average speed is 40mph. If that is the case you would change your oil every 1600 miles give or take 100...I would go more with something like 200-250 hours for a full syn like M1 or GC.

#### Brat57

40 hours of run time will go in the blink of an eye!!! Do the math! 400 maybe, but might be stretching it.

#### n8wvi

Maybe base it on how many gallons of gas you've used? Maybe a combination of the two? I know! One of us oil nerds that's also an EE needs to develop a 'bolt-on' oil live monitor! Ok, I've thought about doing just that, but I'm not an EE. Closes I could come would be a BasicStamp, but they're not cheap. Dave

#### dustyjoe1

Oops you guys are right, 200 would be a nice number. I probably average 45 mph. Much of this average due to 70 mph driving interstate. That translates to a 9000 oci. Maybe a bit much? Maybe split the difference and go 150 that makes me a little more confy at 6750 oci. what you think?

#### doyall

quote:
Originally posted by Brat57: 40 hours of run time will go in the blink of an eye!!! Do the math! 400 maybe, but might be stretching it.
Man, where did you go to school! At 70 mph you'll go 3000 miles in apx. 42 hours. At 40 mph you'll go 3000 miles in 75 hours. At 70 mph you'll go 5000 miles in apx. 71 hours. At 40 mph you'll go 5000 miles in 125 hours. Depending on conditions and your driving style, anywhere from 50 to 100 hours would seem to be appropriate.

#### edhackett

I ran an hour meter in my 1991 Ranger pickup. I was running Amsoil 10W-30 for 200 hours. That worked out to 7-8K miles. I drove 36 miles round trip to work plus road trips, which added up to right at 20K a year. I'd say 100 hours on a non synthtetic, 150 on a HDEO, and 200 on a full synthetic is a good, safe starting place. Ed

#### dustyjoe1

doyall you may want to re-read my post. My grammer may have been a bit garbled, I was typing kind of fast. I said I averaged 45 not 70. what I meant to say was that a lot of the 45 average comes from highway driving at a speed of 70 mph. Sorry about the confusion. Went to school at Penn state - Physics department.

#### dustyjoe1

Thank you edhackett. That sounds like a very reasonable suggestion. I appreciate it. r.

#### doyall

quote:
Originally posted by dustyjoe1: doyall you may want to re-read my post. My grammer may have been a bit garbled, I was typing kind of fast. I said I averaged 45 not 70. what I meant to say was that a lot of the 45 average comes from highway driving at a speed of 70 mph. Sorry about the confusion. Went to school at Penn state - Physics department.
My "where did you go to school" comment was directed at Brat57's suggestion of do-the-math-and-go-400-hours. Anyway, I'll stick with my original numbers even with the semi-syn, as good as it seems to be. EDIT: No problem dustyjoe. [ April 14, 2004, 03:53 PM: Message edited by: doyall ]

#### dustyjoe1

Thanks for the help guys. I think I'm leaning towards edhackets suggestion. I drive mostly highway down here in south tejas so I think I'll start with 150 or so and see how that looks. Appreciate it r.

#### Brat57

School? I was being a little facetious with the 400 comment.

#### Lubricious

quote:
Originally posted by doyall:
quote:
Originally posted by Brat57: 40 hours of run time will go in the blink of an eye!!! Do the math! 400 maybe, but might be stretching it.
Man, where did you go to school! At 70 mph you'll go 3000 miles in apx. 42 hours. At 40 mph you'll go 3000 miles in 75 hours. At 70 mph you'll go 5000 miles in apx. 71 hours. At 40 mph you'll go 5000 miles in 125 hours. Depending on conditions and your driving style, anywhere from 50 to 100 hours would seem to be appropriate.

I already sneer at those who drain expensive synthectics at 5000 miles, 50-100 hours is less miles and even more wasteful. I mean if you won't at least double the 3000 OCI of a regular dino, you shouldn't bother to use synthetic unless you are in frigid climates.

#### TallPaul

Why not run your typical OCI by miles while observing how many hours you rack up and then adjust from there based on UOA results? A really crude method would be to change it every six months. If you only rack up 1000 miles in six months, they likely are harsh short trip miles. If you rack up 6000 in six months, they likely are light duty highway miles.

#### Grossomotto

quote:
A really crude method would be to change it every six months.
Running Delvac 5W40 or a few Amsoil varieties, every six months if fine for a lot of people here.

#### Chris B.

FWIW, I have just over 500 hours on my engine and 16,300 miles total.

#### TallPaul

quote:
Originally posted by Chris B.: FWIW, I have just over 500 hours on my engine and 16,300 miles total.
Then edhackett nailed it down pretty good with 100 dino, 150 HDEO, and 200 synth.

#### zoomzoom

I wonder what is this gallons of fuel theory...after how many gallons of fuel used should you chnage your oil?