dashboard oil change indicator

[edwardh1]

Whats the story on the cars that have the engine's puter tell you when to change oil? Some Mercedes BMW maybe a Chevy or two? What interval are the computers telling people to change oil at?

 

[oilyriser]

I know of a Chevy Venture with that light, and in winter, the interval was 5000 km (3000 miles), and summertime it went up to 9000 km. This was about 50/50 city/highway driving, around Toronto suburbs. Does anyone make an oil change computer that can be hooked up to a car that doesn't have one? It would need a wire wrapped around a spark plug lead to tell when the engine was on, and how fast it was turning, and an outside temp thermometer to tell how many cold starts were done. You might have to tell it how much gas you have bought, too, as well as set some fudge factors for different cars/engines.

 

[Ray H]

In the case of Mercedes, it's not a specific interval. According to the C-class and E-class sales brochures, "... the Flexible Service System in your Mercedes monitors some indications of oil condition, engine loads, rpm, operating temperature and your driving habits to determine when maintenance is really necessary. ..." Sounds good in theory. In practice, Mercedes got slapped with a $23,000,000.00 judgment to pay for engine repair work made necessary by owners' faith in the FSS light. In some cases the FSS indicator didn't illuminate until over 25,000 miles, with an average mileage of all owners in the class-action suit around 15,000 miles. Mercedes said the dealers were at fault for using the wrong oil. A dealers' association spokesperson said that Mercedes' assertion was baloney. Draw your own conclusions. I have no idea how the other manufacturers' systems you listed determine when to change the engine oil.

 

[Quattro Pete]

In my A4, the service reminder is set at 10K miles and it counts down. It does take things like rpms (how hard you drive) and idle time into account, which can affect the interval by a few hundred miles +/-, but more or less, it's 10K miles. 10K miles is also the oil change interval called for in the owner's manual, although given that my engine is turbo-charged and I like to drive it pretty hard, I change it every 5K miles. I've heard that for 2004 model year, Audi is going up to 15K mile oil change intervals.

 

[Al]

My son's GrandAm usually goes off around 6 to 7K miles. I believe it is based on number of starts. Engine running time, rpms. It probably has an absolute upper limit well before 25K miles

 

[GSV]

I know that Mercedes Benz used to go to war with their dealer network in the US over a bunch of issues in the past. Germans tend to overengineer things* and then forget the human element. Remember the German rocket scientists who were a big part of the US space program in the 40s-60s. They basically viewed the astronauts as meat in the can or ballast. The astronauts requesting a window in the capsule drove them crazy. Mercedes engineers probably thought they had a near perfect engine oil monitor but they never assumed some knuckle dragger would pour substandard oil into the sump. * See newer Bosch electric window motors as a classic example. Everybody else uses a detent on the window bar to tell the motor to stop raising or lowering the glass. Bosch had to use a mini computer to count the revolutions of the window motor and calculate when to stop. Ask a VW/BMW etc. mechanic about these. Keep It Simple Stupid ( or Scheißekopf)

 

[JohnnyG]

The GM Oil Change reminder is not a "simple" countdown timer. Depending on the year of manufacture and type of engine design in the vehicle, the MAX change will vary. In other words, a flat tappet, pre 2000 engine will get a max of about 8000 mi. a 2000 and newer roller cam design will get a max of about 12,500 or so. The "points" are deducted based on several factors, temp at startup, idle time, speed/rpm, length of time engine is running (shorter run deducts MORE points) shutdown temp and heat soak to reach ambient. Some cars will give you a continuous "Oil Life Remaining" expressed as a percentage ('99 Cadillac STS) others will just say "Change Engine Oil" ('99 Silverado 6.0L). Stick to the manufacturers oil specs to make the thing work for you.

 

[Kestas]

I participate a lot on the Mercedes web sites. Consensus among the owners on the FSS oil change system is to ignore it. Even during the warranty period, they suggest changing every 6000 miles with the specified Mobil 1 oil, in between the scheduled dealer-required service intervals. After all, why wait for damage to occur? What Ray said is correct. Mercedes has gotten a lot of heat from their owners, to the point that they were forced to extend warranty to 150K miles on FSS engines for oil-related wear problems.

 

[joatmon]

quote:

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Originally posted by Jimbo: Newer BMW's use a maximum of 15,000 miles based on synthetic oil.

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The BMW monitor is based on liters of fuel consumed and it's very possible to exceed 15k. The system uses 5 bars that extinguish at 20%, 40%, etc. My 530i is driven very hard and at 7800, only 2 bars have gone out. My wife's X5 is at 11,900 and 3 bars have gone out. Both are '03s with 3.0 liter engines, mine a 5 speed manual, and hers is a 5 speed automatic.

 

[F1Crazy]

quote:

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Originally posted by joatmon: The BMW monitor is based on liters of fuel consumed and it's very possible to exceed 15k. The system uses 5 bars that extinguish at 20%, 40%, etc. My 530i is driven very hard and at 7800, only 2 bars have gone out. My wife's X5 is at 11,900 and 3 bars have gone out. Both are '03s with 3.0 liter engines, mine a 5 speed manual, and hers is a 5 speed automatic.

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Very true, the system in older cars used to monitor different aspects of engine operation but they simplified it to reduce costs. If you check Bentley manual I think it says that for M54 engines it comes to around 600 gallons of fuel between the changes.

 

[Jimbo]

Each system is somewhat different. The GM Sierra/Silverado system is primarily based on engine hours because trucks in commercial service often see extended idling. My '92 BMW has a system that signals at 10,000 miles maximum (on conventional oil), with reduction factors for low temperatures and operation above 4000 rpm. Newer BMW's use a maximum of 15,000 miles based on synthetic oil.

 

[Chris B.]

My 2003 Silverado savy my oil is at 58% life left at a little less then 3,000 miles so it should come on at 6,000 miles or so.

 

[Bamaro]

This explains GMs monitor: http://www.gm.com/company/gmability/environment/gm_and_the_env/releases/oillife_monitor_041603.html