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Oil change schedule

I have a new Honda Fit which does not have any mileage/time recommendations for oil change, other than the display on the dash.

I already have over 4,000 miles and as yet it displays 70% oil life. The dealer says I must wait til it says 15% before I can have them change it, but at this rate that could be 10,000 miles or more. What do you know about this. My mechanic says they just want to sell me another car in 100,000 miles.

Does the owners manual mention any of this?

If you change the oil earlier what will happen?? It is your car! there must be a schedule of maintenance for your car.

There has to be some indication in the owner’s manual of how many miles to go between oil changes. A maintenance schedule, something!!

I’ll say this much: I would never, ever go 10K miles or more between oil changes. I don’t care what a stupid (and useless, IMO) “oil life” gauge says. No vehicle I own will ever go more than 5K between oil changes, no matter what. It’s just not worth putting it off.

That’s the thing with Honda and Acura. They don’t use mileage anymore and there is no reference to mileage either in the owners manual or the factory service manual. I didn’t like waiting either and talked to the dealer and changed it at the first 5000 mile mark. There was no problem. Now I change at 5000 mile intervals and the minder says about 50-60%. Makes me feel better.

Seriously?? That might be the dumbest thing I’ve ever heard of.

I’m not trusting the longevity of my car’s engine to some computer readout. What a horrible idea.

Just follow the instructions in the owner’s manual. Likely it says to follow the light. Just how long (time or miles) no one knows until it gets there.

It likely will seem long compared to cars without that system because without that system the car manufacturer has to guess how you drive the car. With that system it can monitor how you drive the car and then provide you with more accurate information about when to change the oil.

With out that system the recommended miles and time is based on worse case situation which you likely don't have.

Go buy the dashboard display. The car’s computer monitors all sorts of information and determines remaining oil life.

Time and mileage are really not the best indicators of engine use. The computer knows everything. Trust the computer. The Honda engineers do, and that’s good enough for me.

My Lincoln has the same kind of oil change readout and I don’t pay attention to it either.
Think about what type of driving you do, predominantly, and base your oil changes on that.

You should be able to easily go 5-6k miles between changes if most of your driving is highway only.
A mix of highway/city driving and scale it back to 3-4k miles.
In some severe cases (short hop, city driving only, humid and/or dusty conditions, etc.) then every 2k miles would be the way to go.

Keep in mind that if you were told this by a service manager or writer that very very few of these guys have much mechanical ability and often recite things they know nothing about. Odds are the techs in the shop would say something different.

The anecdotal 3k or 5k oil change is a good average that covers most bases of all the possible variables in driving style, type and owner neglect etc.

An oil monitor actually monitors most of the variables that influence oil change interval and computes a life based of that. Basically it is coming up with a better average if the logic is correct.

In the end do what feels best to you. The car will likely outlast your ownership period either way.

“I’m not trusting the longevity of my car’s engine to some computer readout. What a horrible idea.”

It seems to me the computer, which knows how the car has been drive as well as how far, has a better idea of when it should be changed than the guy who wrote the owner's manual and has no idea how you are going to drive it.

Change when you want to…Just don’t go LONGER then what the monitor system says.

Somewhat off topic…There’s a guy who ran his oil 25,000 miles on his Prius, and sent it to Blackstone Labs, who reported back, that the sample was still good and he could go longer. He used M1 and a single Fram filter.

So who can tell me exactly what does the computer use for reference data to compute the life cycle of the oil. I have forever heard the generalizations, “A certain number of cold starts, hot starts, stops, drive cycles, miles, temp, etc.” But somewhere, it must be written down. Even if it is proprietary info, (and I can’t imagine why it would be) it is in some secret hand book…somewhere. It is probably an algorithm somewhere, but where? Also, what about: “What does it take to set a check engine light for an O2 sensor voltage not within limits?” Or what triggers a “MAF voltage too low” or “Out of range” code? How many times does the computer have to see voltage too high? Just once? Twice during the same drive cycle? What makes the different pending codes turn into actual codes and trigger the CEL? Too often the answer is “it’s proprietary info, the manufacturer won’t release it” so the quest for the info stops. I wouldn’t give up that easy. Now I can understand looking for the col.'s secret recipe, or the recipe for coca-cola, that’s a bit different. Some of this info might be necessary for troubleshooting. So are we gonna roll over and give up? (stepping down from soap box).

You’re in good company, I think BMW uses a similar system, and they even got rid of the dipstick!

I would go by the dashboard display. This system is pretty good and will save you money on unnecessary oil changes.

Unless the car has a spectrum analyzer built in, (and I doubt it) how does the computer know how contaminated the oil is? Or how much of the anti-friction or detergent additives are still useful? I don’t think the computer knows if you’ve been driving in dusty conditions, or really humid climates, or dry desert climates, etc. I’m betting the computer simpy has a baseline set of paremiters and compares what it sees to what it expects, and comes up with a percentag of oil life remaining. One more reason not to trust the computer.

I have the dashboard diplay that gives percent of oil life remaining on my 2006 Chevrolet Uplander. I don’t know what algorithms are used, but it drops to about 5% oil life remianing after 3000 miles in the winter, but I may go twice as far in the summer before it shows that the oil life is depleted. This makes sense to me and is exactly what I did on my previous cars that don’t have this feature. Something else I’ve noticed is that the percentage of oil life remaining is not a linear function of the mileage. I may drive 3000 miles and it indicates that I still have 50% oil life remaining. Under the same conditions, I may drive the next 1000 miles and it indicates that the vehicle is due for an oil change. I’m certain that the indicator system isn’t aware of the type of oil in the crankcase–it goes about the same distance before indicating an oil change whether I use regular or synthetic oil.

Our other vehicle, a 2003 Toyota Uplander has a maintenance light that goes on after 7500 miles regardless of the driving conditions. I never would drive it this distance between oil changes. Our independent garage forgets to reset the light, so I have had to reset it. The procedure for doing this is not referenced in the index of the owner’s manual, so it takes some searching for me to find out how its done. The procedure is to turn the ignition switch on and make certain that the odometer is reading the actual miles and not the trip miles. The key is then turned off, one holds the odometer reset button and turns the key to the run position. The light flashes a certain sequence and then goes off. This makes me think that this system on the Toyota goes strictly on miles.

You have to remember that a Prius…the engine doesn’t run all the time like it does on other cars. Second…ONE analysis does NOT mean you can do it all the time. There are way too many variables.

I would guess that the computer uses algorithms based on distance driven, distance between starting and stopping the engine, and perhaps whether the engine fully warmed up between starting and stopping the engine. I do know that the percentage of oil life remaining is not strictly based on miles traveled. The computer makes the same guess based on data that I do when deciding whether or not it is time to change oil.

I worked for farmers when I was much younger. The newer tractors would indicate hours at a certain rpm. The tractor would be serviced after a certain number of hours. I don’t think the Farmall F-12 had such a meter–servicing was done on a “by golly by guess” method. The F-12 had a magneto ignition and was started with a hand crank. I regarded farmers who had electric start on the tractors as wimps–real men start their tractors with a hand crank. (If I did farm work today, I’m certain I would be a wimp.)