I see all this talk asking how often to change oil,how many miles??? I have always thought it depends on the type of driving, city or hiway? Well years ago I picked up on something that I have used on the last 7 or 8 cars of mine that I feel is better than an odometer for oil changes and that is a 'HOUR METER'. Kind of a cheap GM oil life monitor. You stop at a stop lite, it keeps counting, idling in the food line at Mcdonalds, it keeps counting, as long as the engine is running, it's still counting,etc. can't say that for an odometer. Boats, planes, genorator's all use them. Now how often do you change the oil? years ago I read an article about some new engine that had just completed a 4000hour test which was said to have simulated a 100,000 mile run at an average of 25mph which they, the engine maker said was what the averge driver does. This same company says to change oil every 3000miles for severe use and 7500miles for hiway. 3000 at 25mph = 120hours and 7500 at 25 = 300hours which sounded like alot of hours to me and 7500/120hours = 62.5 mph which is faster than I average(42mph) so I went for the happy medium of 200hours which was backed up when I found that Ford recommends a 200hour oil change for vehicles that idle for long periods of time under 'severe' conditions. Well 200 hours takes me about 8000 to 8400miles at an average overall speed of 42mph per the hour meter in my every day driving life of mostly hiway driving not considered to be 'severe'. The last car today has 240+ miles on it, still not using oil after a life of re-refined/new dino. Just had to write this being I have yet to see much talk here about hour meters.
poor man's 'GM' oil life monitor
- Thread starter gudmund
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Excellent idea gudmund! You're brilliant! Cheaper than the GM oil life monitor and probably better since it is immensly simpler. Always wanted an hour meter and now you have given me a very good reason to get one. I am about to order one up from JC Whitney. I assume the hookup is simply one wire to a power source that is on only when the ignition is on (key on power, not accessory power) and the other wire to ground.
[ January 16, 2004, 12:31 AM: Message edited by: TallPaul ]
[ January 16, 2004, 12:31 AM: Message edited by: TallPaul ]
Sounds like a GREAT idea to me. I think it could be a supplement to the GM oil life monitor. AS in " change oil every 200 hours or when the oil monitor tells you to, whichever comes first."
I'm sure this idea will catch on with most of us on this board. Maybe later we can take a "poll" and decide what "servere service" REALLY means.
I'm sure this idea will catch on with most of us on this board. Maybe later we can take a "poll" and decide what "servere service" REALLY means.
I used an hour meter to determine oil changes on a 66 Mustang I had in 1970. I don't remember what hour interval I used, but I do remember being shocked at how low my average speed was.
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I like the idea......a lot.
hmmmmmmm, what would be really good is if it indexed an extra hour or two every start. Would add an extra level of protection without too much additional effort.
There's an invention out there for someone to make money on.
hmmmmmmm, what would be really good is if it indexed an extra hour or two every start. Would add an extra level of protection without too much additional effort.
There's an invention out there for someone to make money on.
Excellent idea. And the first thing I'm going to put it on after I buy one is my lawnmower, that calls for oil changes after 25 sweaty hours.
This is from the GM Tech Line (as I copied it from another net bulletin board):
"Oil life is affected by many factors other than just miles driven. The type of driving, temperature, and engine load all play a part.
That’s why GM has developed the GM Oil Life System, an electronic watchdog that keeps track of all these variables and notifies the driver when it’s time to change oil.
Briefly, the Oil Life System is programmed with a certain number of engine revolutions. As the engine runs, this number is reduced until it reaches zero, and the Oil Life light or message comes on. But there’s more. Operating the engine under low or high temperatures, and under high load conditions subtracts (penalizes) extra revolutions, so the light comes on sooner.
Changing engine oil according to actual need rather than an inflexible schedule provides several benefits.
First is simpified determination about when to change oil. No more decisions about “normal” conditions vs. “severe” conditions. Second is reduced operating costs for GM’s customers, who now have to change oil only when it’s needed. Third is minimizing the amount of used oil that must be disposed of. And fourth, engines will always be running with sufficiently fresh oil, for long life.
These benefits will be realized only if engine oil is actually changed as indicated by the GM Oil Life System.
Some customers “get it” when it’s explained to them. Others may be reluctant to deviate from traditional oil change interval charts. So, part of the responsibility falls on retail service people to help get the message out."
Also a good article at Noria.com gets into the technical details behind how the oil monitor system works:
http://www.noria.com/learning_center/category_article.asp?articleid=77&relatedbookgroup=Lubrication
[ January 16, 2004, 10:52 AM: Message edited by: TallPaul ]
Wouldn't a "tach accumulator" (I made that term up) provide a better measure than hours? For example, driving at highway speeds (where the engine may be turning at 3000 rpm) would be worse than sitting at a stoplight (
It would also take into account acceleration better than just time....
It would also take into account acceleration better than just time....
Don't bother applying for a patent
Quite a few "hour meters" in tachs on older vehicles with mechanically driven tachs were actualy just what you described instead of hour meters. They just called them hour meters.
I think that ight have also been common on aircraft engines but am not sure.
Yes, aircraft have both conventional hour meter and a tach time meter. Engine maintainance is based on tach time, which is dependent on RPM.
Straight run time is better for automotive use, as the highest wear is at idle and stop and go. The least wear an automotive engine sees is fully warmed up and running at highway speeds.
I installed an hour meter in my 1991 Ford Ranger when I bought it. I used Amsoil 10W-30 and changed it at 200 hours. This was somewhere between 7500 and 8000 miles for my driving habits.
Ed
Straight run time is better for automotive use, as the highest wear is at idle and stop and go. The least wear an automotive engine sees is fully warmed up and running at highway speeds.
I installed an hour meter in my 1991 Ford Ranger when I bought it. I used Amsoil 10W-30 and changed it at 200 hours. This was somewhere between 7500 and 8000 miles for my driving habits.
Ed
Are you the Hackett that published the prototypical oil characteristics table. If so you get a big "we're not worthy"!
wait, how is idling bad? last i checked, cylinder pressures at idle are nowhere near that of under load. were talking sub 200psi at idle here guys, thats gotta be real easy on the rod bearings and such.
Maybe you are right about cylinder pressure, but the inefficient fuel ratio tends to dilute the oil a tad as I understand it, especially if you have an old fashioned carb instead of fi....and diluted oil is bad.
The reason idleing is bad for the oil is becuase of fuel dilution from being to rich. Valve overlap causes fuel air mixture to blow back into the intake tract. One the motor is up to speed this process stops for the most part.
the o2 in any modern exhaust system should compensate for any reversion though. any air/fuel mix that got bounced back into the intake tract will be burned on the next valve opening, and the o2 should see this richness and compensate for it by leaning out. modern fuel injected engines dont run rich at idle, they run lean. (well most fi, that is factory and not a haltech or megasquirt or other adjustable fi anyways) anyone with a o2 gauge knows this.
the 02 sensor will tell the computer its rich, so it will lean out accordingly. then it gets too lean, and richens it up, gets too rich, and leans out. its a never ending cycle at idle, and even cruising around. your never set at 14.7, its awalys changing as the computer constantly tries to find optimum.
carbs dont really count, i mean what modern automobile comes with a carborator? heck, even harleys have fuel injection now!
the 02 sensor will tell the computer its rich, so it will lean out accordingly. then it gets too lean, and richens it up, gets too rich, and leans out. its a never ending cycle at idle, and even cruising around. your never set at 14.7, its awalys changing as the computer constantly tries to find optimum.
carbs dont really count, i mean what modern automobile comes with a carborator? heck, even harleys have fuel injection now!
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