Posted on 06/17/2008 7:19:00 AM PDT by Disturbin
According to a recent study by the California Integrated Waste Management Board, 73 percent of California drivers change their oil more frequently than required. This same scenario no doubt repeats itself across the country. Besides wasting money, this translates into unnecessary consumption of $100-a-barrel oil, much of it imported.
Using 2005 data, the Board estimates that Californians alone generate about 153.5 million gallons of waste oil annually, of which only about 60 percent is recycled. Used motor oil poses the greatest environmental risk of all automotive fluids because it is insoluble, persistent, and contains heavy metal and toxic chemicals. One gallon of used oil can foul the taste of one million gallons of water.
It’s been a misconception for years that engine oil should be changed every 3000 miles, even though most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions.
Greatly improved oils, including synthetic oils, coupled with better engines mean longer spans between oil changes without harming an engine. The 3000 mile interval is a carryover from days when engines used single-grade, non-detergent oils.
For several years, automakers like General Motors, BMW, and Mercedes-Benz have installed computerized systems that alert drivers via an instrument panel light when it’s time to change oil. As an example, the General Motor Oil Life System (GMOLS) analyzes the engine temperature, rpms, vehicle speeds, and other driving conditions to calculate the rate of engine oil degradation. Then, software calculates when the oil needs to be changed. Other systems work similarly.
Because of the many external conditions and parameters that have to be taken into account, calculating the precise maximum service interval using mathematical models alone is difficult. Now, Daimler AG has developed a more direct and precise way to monitor oil quality directly on board a vehicle.
Daimler uses a special sensor integrated into the oil circuit to monitor engine oil directly. Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change. Daimler uses the oil’s “permittivity,” that is, the ability to polarize in response to the electric field. If the engine oil is contaminated by water or soot particles, it polarizes to a greater extent and its permittivity increases.
To evaluate the quality of the oil, permittivity is measured by applying an AC potential between the interior and exterior pipes of an oil-filled sensor to determine how well the oil transmits the applied electric field.
Because not all impurities can be measured with sufficient precision via the electric field method, Daimler also measures the oil’s viscosity to detect any fuel that may have seeped into the oil. Daimler researchers measure viscosity while the vehicle is in motion by observing the oil's side-to-side motion in the oil sump. The slower the oil moves, the higher its viscosity. This movement is registered by a sensor and the viscosity is calculated on this basis.
A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation.
Three vehicles, Mobil 1 in all of them, change oil every 6 month or 7500 miles whichever comes first and have never had a problem.
Once had a VW Fox wagon which was generally a piece of s**t, but the engine never gave out. Used Mobil 1 or Castrol Synthetic throughout its 135K life changing oil every 6-7K.
Or an AMC Gremlin
What you say could be entirely true. (Caveat: a single experience is just that)
My folks have a 2000 Toyota Avalon. Just to show how little they drive it, it has 35K mi on it. I suspect they have never changed the tranny fluid. Auto, of course.
An engine light came on, and we had it scanned at the local dlr. Scan came back “tranny shifter solenoid”. OK, so Toyota has a very logical 3-step process for diagnosing/fixing this. Nobody expects a tranny to go bad at 35K.
1: You just flush the tranny, hoping that a piece of gunk is interfering with the shifting. (They are aged 90 & 91, I am doing all the driving now, and before/after the light came on, I detected no difference in performance) About $300-$400. Light returned after about 3 days post service.
2: You replace the solenoids. Obviously this involves far more serious work, dropping the pan, getting in there, etc; About $700. Light returned after about 3 days post service.
3: Replace the tranny. About $2800. Ugh.
We’ve completed steps 1 and 2. What I have NOT done is to reset the warning light, because a fault only has to occur ONCE and the light will latch on, permanently. This can be done away from the dealer by disconnecting the battery for 15 mins or so.
Not eager to proceed to step #3 as you might imagine.
I remember hearing a race car driver say that the 3,000 mile “rule” for oil change is not really true, that 10,000 mile interval is sufficient - but went on to say that he went ahead and followed the “rule” anyway every 3,000 miles just to be doing apparently, but said there was really no real basis for it.
There is a member of one diesel performance forum I visit once in awhile that has a Ford Powerstroke Diesel that he runs a Group IV synthetic (100% synthetic) oil in with a bypass filtration system. He has not changed oil in close to 50,000 miles (last I knew.) He does regular used oil analysis and the oil continues to show practically new in terms of contaminants, TBN, etc.
Some of the new Cummins over the road engines have systems on them that “recycle” used motor oil on board. It mixes the old engine oil in the diesel and burns it as fuel. The operator adds new oil periodically and changes the filter. The 2010 emissions may bring and end to this innovation.
I believe in Mobile 1, no doubt as that's all my 2003 Ford Ranger has seen since the new engine off the lot saw 1000 miles on it and its first oil change. Using 5W-30 Mobile 1 in it.
What kind of car was your last car?
>>>>But, if switching from Dino-oil to synthetic, you should flush the engine first.<<<<<
Thats a myth.
Now I have an old car, a 69 VW. I do the 3000 mile thing, religiously. I tried synthetic, caused low oil pressure at idle when the engine was hot. The air cooled engine runs hotter than your water cooled ones. So I use Shell Rotella 15W-40, which is designed for diesel engines. I’ve had no pressure issues since I started using it.
Ditto my sentiments. On the cars I drive regularly, I do them at 3k.
For antiques, it’s usually twice a year at less miles.
” ... most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions.”
And most auto manufacturers state that ABNORMAL driving conditions include towing a trailer, short trips, and stop-and-go traffic.
Sounds like most of my driving.
Another thing the greenies did was have the amount of zinc dialkylditiophosphate (ZDDP) additive in lube oil reduced. No big deal on modern cars with roller lifters, but for classic/older cars with flat tappets it is death to camshafts.
Must use racing oil (like Royal Purple) or diesel truck oil (like Shell Rotella), but I hear that even the diesel truck oil will have their ZDDP reduced for emission standards.
I know some luxury models include all routine maintenance up to 100K these days, but this is how some of the other manufacturers are sticking it to drivers: instead of a “change & lube”, it’s now an “interval service” including crap like $59 charges for “visual inspection”. It’s like the “processing fee” when you buy a car, just some made-up charge for no good reason.
One word: AMSOIL
'93 Plymouth Sundance. Anecdotally speaking, I think very few of those cars ever got past 100,000 miles, but I admit I've never done a complete survey.
Bingo!
File this one wherever you put “Save $2 A Gallon”. ;’)
All you need is a stray electron to make the sensor go to fault. It could be in the sensor itself or in the harness or in the computer. I’ve also seen faulty sensors replaced with a new, but faulty sensor. My point is that it may have nothing to do with the tranny at all. There are ways to test the sensor itself as well as the computer and harness. Whther or not it is worth doing is another matter, but if you spend $2800 on a new tranny and the light still comes on, you are going to wish you had. If it were me and the car runs fine otherwise, I would just drive it until it breaks down.
I was told by me dealer that 3000 is recommended for the bulk recycled oil, 5000 for brand new oil and 6000 for synthetic. Can anyone confirm or deny this for me? Thanks
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