Joined: Aug 02, 2006
Location: McLean, VA, USA
Mon Oct 23, 2006 3:19 pm
Automotive dealers in this country are really smart. They managed to create public opinion that gives them return service customers three times more often than in any other part of the world. Huge money are made on this. It is probably the biggest source of dealership income.
I got tired explaining to people in this country that they don’t have to change the oil every 3000 miles. I got tired explaining that this does not do any good to their engines and hurts their wallets and our shared environment. I got tired explaining that manufacturers spend millions and millions on research and testing to make cars more reliable and to decrease cost of ownership, including increasing service intervals and decreasing service complexity.
And dealers did not spend a penny on the research. They are smarter. They spend just small part of those huge sums on supporting the lie that became a common knowledge among American drivers. They get even smarter. When you tell them what your owner’s manual says about oil change interval, they reply “you know, we have severe driving conditions here”. In DC area?! Come on, this is not Alaska, and not New Mexico. But people keep going to dealerships every 3000 miles to waste their dollars and spoil the environment.
A quote from Honda website (bold mine):
How often should I change my oil after the first service?
Refer to your owner's manual for the recommended service intervals. Separate maintenance schedules are listed for "normal service" and "severe service." Read the description of severe service carefully. Most vehicles will fall under the normal service category. Note that the service intervals are listed by time in addition to distance. Your oil should be changed at whichever interval, time or distance, occurs first.
There is absolutely no benefit in changing your oil more frequently than recommended in your owner's manual. This will only increase your cost of ownership, and create an unnecessary burden upon the environment by increasing the amount of disposed oil.
Do not exceed the recommended maintenance interval. Oil eventually deteriorates and loses its ability to protect your engine, due to heat, friction, and exposure to exhaust components. Engine oil contains special additives to enhance the oil's performance, and these additives are also broken down or consumed with distance and time. Engine damage can occur if the proper maintenance schedule is not followed.
I've changed oil in a lot of different vehicles. In my civics, I've never had a problem waiting 5 or 6 thousand BUT...
My wife drove a 98 Saturn when we met. I started changing the oil for her and noticed that within 2000 or 3000 miles it turned to sludge. I don't mean that it stopped being clear. Its color and texture turned to something like chocolate syrup!
Not only that, but if you took off the oil filler cap and looked inside the engine, it was just BLACK from deposits.
I never did figure out what was up with that car. I just managed to get blue book value for it and walked away from Saturns forever!
btw.. I didn't cheat anyone selling the car. A tree fell on it scratching the heck out of the paint. I subtracted the insurance check from the price of the car when I sold it. Some guy loved saturns and was happy to drive away in a 98 for $1100
From the constant cold-hot cycles the oil breaks down, and losed it's properties. If you use quality parts yes it is possible to go for long periods of time, but why? Aged oil becomes sludge, it is a proven fact. I've seen cars that were super heavily sludged up from just sitting on a parking lot for a really long time. Most drivers, 5000 is fine, for me it is 3000. I like my car too much to not change my oil frequently, even if doesn't do much, I still feel better.
Most newer vehicles have sensors built into the engine that can sense when it is time to change the oil. I recently bought a Chevy Equinox and it is supposed to need an oil change around every 10,000 miles. Always refer to your manual to find out if your change oil light is sensor activated, or if it is mileage activated.
I didn't know that you don't need to change your car's oil every 30,000 miles so that's good to know. Thanks for the info and I can see what you mean about how hard that can be on the environment when you have millions of people doing that.
OK, here's a question for you car folk...we live very close to my wife's work, so she doesn't put many miles on her car. This is in San Diego, CA, USA, so the weather is pretty mild year round.
It can take, just an offhand guess, over six months for her to go 5,000 miles. So, when it comes to changing oil is there a time frame that should be used for low mileage drivers? Three times a year? Or is mileage the only determining factor?
Thank you Misha for starting this thread. This is only one of hundreds of ways the dealer will cheat you. I know. I once worked for one. Dealers are not the only cheaters. I drive an average of 10,000 miles per year. I have my oil and filter changed every 6 months at an oil change business called Oil Can Henrys. They always remind me that I should never exceed 3,000 miles and try to sell me everything else that I don't need. I realize they are a business and need to make money, they just wont get extra from me. One thing they do puzzled me until I received information from one of their customers. They always try to sell you synthetic oil. To me this seems counterproductive. They would make a substantial monetary gain on the initial service but with the change interval of synthetic being 10,000 miles plus they would loose opportunities to sell their other uneeded stuff. I learned from the other customer that they told her. "Synthetic oil is worth the cost because it will give you double the engine life but no matter what type of oil used it still needs to be changed every 3,000 miles". In my opinion that is outright fraud!!!
Actually, it isn't so much of a fraud. Yes, changing the oil categorically each 3,000 miles (about 5,000 kilometers) is wrong. Modern, premium-rated, fully-synthetic motor-oils, newer oil filters and air filters and engine control units - allow to stretch oil replacement intrevals to as high as 18,000 miles or two years.
However! This is only true if the motor-oil is really high-quality and if life has been kind to it. Unfortunatly, modern engines work in higher loads and smaller oil passanges and since they are smaller and more enviornmental friendly - they hold less liters of oil.
Even more unfortunatly, most cars drive in conditions that put extra strain on the motor-oil and the engine. In this case, the only solution is to replace the motor-oil sooner; Usually not so early as each 3,000 miles - but replacing the motor-oil more frequently is the only solution to keep the engine operating well.
The number one cause of premature motor-oil degrading is urban driving. Many modern cars drive in short trips inside the driver's hometown. This means that the car is driven for periods of time that does not allow it to get up to working temperature. This means that the engine is burning less of the fuel it recieves, so more unburnt fuel, soot (which is semi-burnt fuel) and water droplets - all drop down.
Since the piston rings are also not heated and expanded - they cannot keep these residues out of the crankcase - where it meets the oil. The oil is also cold and it's disperents and detergants also cannot manage to clean out these contaminations effectivelly.
And it this isn't bad enough - the driving style in cities involves frequently accelerating and deceleration (stop and-go) which makes for further soot on the valves and sparks - but also on the motoroil. Low speeds, low revs and idle revs in particular - all increase the amount of soot and reduce the ventilation of the crankcase.
Eventually, when the engine is turned off - the circulation is cut off and the residues cause the motor-oil to degrade and with the long-term effect of oxidiating - it will deteriorate quickly into sludge. If the motor-oil is cheap or if it's not replaced in time and especially in hot weather - the sludge could cause engine seizure.
Flushing the engine is supposed to remove the sludge but it can cause compression issues (since the soot on the rings forms some isolation) and it can cause some slush to be washed up the valvetrain or into the oil filters - plugging it and cutting off oil circulation.
The only solution is to use a high quality oil and replace it each 8,000 miles or each year (the earlier of the two) along with the oil filter. I would also suggest that such engines will be opened at the head and crankcase after 120,000 miles to check for any sludge buildup and flushing the engine might also be necessary. A more subtle driving style and avoid needlessly short trips is also good.
Other situations where the oil should be replaced earlier is when the engine is working hard in high revs very frequently (such as with cars used for performance driving or track driving) or for towing very heavy loads - where oil replacement can be cut down to as much as 3,000 miles or six months, with a molybedinium disulfit additive for further protection, frequently opening up the engine to clean it (so much as each 20,000 miles) and using a regenerative oil additive that helps reform worn parts.
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