jmac72187

I know mobil 1 and royal purple are the two most popular, but how long do these last before an oil change? I though I had read a thread about oils that were guarenteed for more than 10k miles? Is this true?

cliffyk

Mobil's warranty is:[/align][/align] [/align]I didn't find any published warranty on Royal Purple's site--so the bottomline re: Mobil 1 or RP would seem to be NO...[/align][/align]And there's fat chance of ever proving that any equipment damage was "directly caused by a defect or malfunction of a Mobil lubricant", trying to squeeze too many miles out of does not constitute "defect or malfunction".[/align][/align][/align][/align]

Colorado_Mustang

Amsoil's warranty: AMSOIL INC. of Superior, Wisconsin hereby warrants that its lubricants are fit for use according to the written recommendations of AMSOIL INC. and in applications specifying one or more of the standards set forth in the product data bulletins and product labels. AMSOIL INC. further warrants its products to be free of defective materials, design, and workmanship.

Drain interval is 25k miles or 1 year.

jmac72187

so basically I could change my oil with AMSOIL in the spring after my car comes back out and then change it again the next spring? I really don't want to hurt my car, I was just intrigued by something I remember reading.

Colorado_Mustang

Yes you could. I change mine in the middle of summer for the '03, and in the fall for my '93.

Lizardbreath

I would change it every 10k miles if you drive it hard though.

Colorado_Mustang

No need. Just follow the oil manufacturer's recommendation. Racing oils are obviously different than day to day, but the 25k/1yr change is similar to the severe duty you'll see in most auto manuals.

jmac72187

I drive my car like a granny. I am 19 and paying for the car and my insurance by myself and going to school. I don't like to hurt it. I rip it up maybe once every week or two but then I feel bad for it and don't do it again. I probably only put about 7k a year on it because I only drive it 2/3 of the year.

jayel579

3 months or 3000 miles, thats what I go by. I don't care what oil companies say about synthetics lasting longer even if they do last for more then 10,000 miles. You don't change your oil because it breaks down, you change your oil to get the "dirt" out of the motor.

Colorado_Mustang

A lot of that "dirt"(aka sludge) is from the oil itself. The variations in the molecular size of regular oil allows different parts of the oil to burn off or gel before the majority of the oil. This will deposit itself in the engine (sludge) and thicken the oil overall. Synthetics have uniform molecular size, which is why it won't boil off or gel as quickly. It also resists sludge for the same reason. After 12k miles, the oil in my engines is still clear.

Now, if you switch over to synthetic with a higher mileage engine, the oil will darken quickly. This is because the oil will be picking up the sludge left behind by the regular oil and keeping it suspended either until the filter removes it or the oil is changed.