Switching back and forth

Not open for further replies.
Nov 16, 2002
Does it hurt to switch back and forth with different oils? I ran M1 for 80k miles and have been using Amsoil for the last 30k. I'm going to go back to M1 for convienence reasons and I also want to compare with some analysis. Some on here have said you should stick with one.

How would analysis results be affected from switching to M1 after using S2000?

[ February 23, 2003, 11:33 AM: Message edited by: buster ]
One additionsl thing. Each oil will give a different (even though slight) amount of seal swell/shrinkage. I just have the feeling that you are at higher risk as far as a leaking main seal by switching frequently. I hasten to add this is just an opinion. Please feel free to prove me wrong. That added to what TooSlick has mentioned has caused me to rethink my idea about switching too many oils in a vehicle. I am instead going to compare by using more cars with different brands of oils.
That is a good point Al. I think though that many people are never using the same brand often that it really doesn't matter. One all my previous cars, I used various brands and never had any problems. They were dino oils though so I don't know if that makes a difference.

If anyone has any idea on this, I'd appreciate the input. Thanks.

[ February 23, 2003, 08:56 PM: Message edited by: buster ]

Every oil has a different additive chemistry and it takes a while to work it's way into the engine - this seems to be particularly true with Redline Oil. In this case I'd run Mobil 1 several times in a row and test the second or third batch you run. I'd run the Mobil 1, 0w-30, since you have been running 0w-30 for the past few changes.

The engine looks to be in excellent shape after the AutoRX treatment, so I'd expect you to get good results. The wear rates you got recently with the Amsoil 0w-30 were very low ....

As long as you're keeping the intervals at a lower level (under 6k) it's ok, but it's still better to stick with one oil as it'll give you better overall results in terms of TBN retention, oxidation, etc. The first oil analysis with a new oil will typically not be the best one, it's the second and third intervals where it really shows what it can do.
Back in the mid 1960's, at my dad's service station, we had a government vehicle that we serviced regularly. Every time we changed the oil and filter we put a different brand of oil in it as a test. After 60,000 miles it had only used 1 quart of oil.

We had better luck than the government employees. They were trying to figure how to get rid of the new threat---fire ants.

Not open for further replies.