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WaterDR · 02-14-2005, 08:04 PM

Man I HATE these threads about oil changes, so I guess it was only a matter of time for this one to pop up around here. People get so emotional when it comes to oil.

Quite frankly, most people do not understand oil and much of what you here is jsut plain myth.

A few years ago, a great study was performed to test all these theories about oil change intervals and the benefits of synthetics. My employer at the time (a large Fortune 500 company with 10,000+ vehicles on the road) used this study to increase the length of miles between oil changes.

For the study, they took dozens of NYC cabs. The motors were pulled and tollerances were measured. Then they were driven for over 60,000 miles. Some cars used synthetic, some used mineral, some used the wrong viscosity, some never changed the oil at all. Then, after the test, the motors were pulled apart and re-checked.

Now, I am doing this from memory, but this is what was learned.

1 - The most damage ocurred to engines where the wrong viscosity was used.

2 - When synthetic oil is used, you can double or triple the oil change interval.

3 - Mineral oil can be safely run something like 8,000 miles.

4 - Changing oil too frequently actually increases the risk of major engine failure because of the increased liklihood of putting the wrong oil in, not tightening the drain plug, getting foreign material in the motor, etc...

If you use synthetic and you change your oil every 3,000 miles, you might as well burn your money, but hey, it's your money.

Another thing to consider is the financial payback. And for God's sake, if your are leasing, you must be insane to change the oil any more frequently than what the owner's manual states (7500). Why would anyone do that? Makes no sense to me.

Let's assume there are two cars and two owners. Chris from MT buys a new Mustang and he wants to keep it for 150,000 miles. Mad Matt does the same. Matt buys cheap mineral oil and changes his oil every 3,000 miles. Chris buys Mobil One and changes it every 3,000 miles.

Matt buys a cheap Fram filter for $4.00 and buys his oil for about $6.00 at Walmart. Matt does his changes himself and it takes him about an hour from start to finish including the time spent disposing of the oil, picking up a filter, etc... and having a beer. Let's use $12.00 an hour for his time. That's a total cost of about $22.00 per change which is about what a Jiffy Lube charges (which is why I don't do my own...I use a much higher value for my time).

Chris buys expensive K&N oil filter because he owns MT and is rich. He pays $12.00 per filter and buys the Mobil One at Walmart for $18.00. That's $42 per change using the same labor rate.

Over the life of the car, Matt spend a total of $1100 for oil changes and Chris drops $2100.

So the big question is: Did Chris wisely spend an extra $1,000?

02-14-2005, 08:04 PM	#13 (permalink)
WaterDR Administrator Join Date: Sep 2004 Posts: 6,374	Man I HATE these threads about oil changes, so I guess it was only a matter of time for this one to pop up around here. People get so emotional when it comes to oil. Quite frankly, most people do not understand oil and much of what you here is jsut plain myth. A few years ago, a great study was performed to test all these theories about oil change intervals and the benefits of synthetics. My employer at the time (a large Fortune 500 company with 10,000+ vehicles on the road) used this study to increase the length of miles between oil changes. For the study, they took dozens of NYC cabs. The motors were pulled and tollerances were measured. Then they were driven for over 60,000 miles. Some cars used synthetic, some used mineral, some used the wrong viscosity, some never changed the oil at all. Then, after the test, the motors were pulled apart and re-checked. Now, I am doing this from memory, but this is what was learned. 1 - The most damage ocurred to engines where the wrong viscosity was used. 2 - When synthetic oil is used, you can double or triple the oil change interval. 3 - Mineral oil can be safely run something like 8,000 miles. 4 - Changing oil too frequently actually increases the risk of major engine failure because of the increased liklihood of putting the wrong oil in, not tightening the drain plug, getting foreign material in the motor, etc... If you use synthetic and you change your oil every 3,000 miles, you might as well burn your money, but hey, it's your money. Another thing to consider is the financial payback. And for God's sake, if your are leasing, you must be insane to change the oil any more frequently than what the owner's manual states (7500). Why would anyone do that? Makes no sense to me. Let's assume there are two cars and two owners. Chris from MT buys a new Mustang and he wants to keep it for 150,000 miles. Mad Matt does the same. Matt buys cheap mineral oil and changes his oil every 3,000 miles. Chris buys Mobil One and changes it every 3,000 miles. Matt buys a cheap Fram filter for $4.00 and buys his oil for about $6.00 at Walmart. Matt does his changes himself and it takes him about an hour from start to finish including the time spent disposing of the oil, picking up a filter, etc... and having a beer. Let's use $12.00 an hour for his time. That's a total cost of about $22.00 per change which is about what a Jiffy Lube charges (which is why I don't do my own...I use a much higher value for my time). Chris buys expensive K&N oil filter because he owns MT and is rich. He pays $12.00 per filter and buys the Mobil One at Walmart for $18.00. That's $42 per change using the same labor rate. Over the life of the car, Matt spend a total of $1100 for oil changes and Chris drops $2100. So the big question is: Did Chris wisely spend an extra $1,000? __________________ Black 2000 GT Vert: Novi-2000 with Intercooler (375rwhp @ 9 psi); Tune by Kauffmans; Roush 380R Body kit; Steeda Subframes; Steeda Strut Tower Support; Deep Dish Bullets; FRPP 4:10's; SCT 4 Position Chip with four custom tunes; Steeda CAI; C&L Pleum; BBK 75 TB; SLP Loudmouth; SLP Catted X-Pipe; Bullitt Suspension; UPR Conrol Arms; Focus Fuel Pump My Car My Email