switched from mobil 1 motor oil to amsoil a couple of months ago, seems to be performing good. Any thoughts?

 

Amsoil holds up better under oxidation tests. They are both good oils, but amsoil is a little better. Just make sure not to go past 5K on your changes.

 

I used Mobil One and have for years.

Delvac 5w40 for my dieseland Mobil One 5w30,&, 10w30
for my Disco.

Mobil is much easier to find, the Mobil One oil filters are very good oil filters.

 

okdiscoguy - why shouldn't you go past 5k for oil changes? my owner's manual recommends 7500.

 

I ran an oil analysis on my drains. Right around 7500 I started seeing high carbon and fuel contents. I have almost 100K on my engine, and while the management systems are different, mine is the same as a D2. If you have meticulously maintained your engine (mine wasn't), using 91+ octane all of the time and fuel treatments regularly, you are probably ok. These motors tend to carbon up easily, clogging injectors and making things worse.

The oil just gets too dirty...

Also, unless I am mistaken, that is the interval for the dealer supplied synthetic....conventional oils for sure won't support that interval...

 

The guy I bought my '97 from had always had it serviced at the dealer since new. 7,000-8,000 mile oil changes. It had 152 and change when I bought it in April '07.
I use Mobil 1 15w50 and I just did the 170,000 mile oil change. I change mine every 5k. I dont worry about the 100's, just every time a "5" or a "0" shows up third from the left I change the oil.
I think that like conventinal oils synthetics are about the same. Name brands being about equal to one another. I use M1 because it is easy to find. I used to use Castrol Syntec but almost nobody carried the weight that I wanted.
Just pick a brand and stick with it.

 

What fuel treatments are recommended? And how often?

 

Who about Royal Purple, from what I am hearing they will give both Mobil1 and Amsoil a run for their money.

As for gas additives, my 3 favorites are, from the cheapest to the most expensive, SeaFoam, Chevrons Techtron and the all time best B&G's 44K.

 

RP will kill everyone, but it is more expensive and harder to find. I would have commented, but didn't want to sound like a salesman. If I ever make it to a national rally, I'll throw my bearing tester in the back to show people. I was amazed the first time I used it. I sell it, but now I believe in the product. I tried to make it fail by pulling the oil bath out and filling it with water. It just kept running. The film strength is amazing.

I agree with you in the same order on the additives. I have a can of 44k waiting to get thrown in for the trip to Dallas this weekend...

 

In a Corvette magazine last year, the magazinedid a test with Royal Purpal vs other common synthetics to see if their claim of more HP (it'sRP's claim) was reall true, or just hype. The magazine was skeptical. It was an independent test, and they indicated they were not out to sponsor the product in any way (take it for what you want). They used a well known Dyno shop. Anyway,the results indicate that itDID provide a couple HP more.

Personally, I've used Citgonon-synthetic oil for years. That's all I use. Change every 5000 miles. I use AC Delco or Motorcraft filters. My daily driver Cadillac has 230k mi, my wife's Jeep G/C has 196k, my Chevy truck (359)has 245k. I have a Caprice that I'm restoring that I drove up to278k mi! It's about 85/15highway/City miles. None of these engines are oil burners and none tic or make excessive noise. They all run great and I've never had one apart, except for my Tk'sleaky intake gasket and it looked nice and clean inside.I know guys who only useWalmart branded oil and have high-mileage engines.My personal feeling is that oil-type arguments are way overrated. Synthetic IS better according to almost every test I've ever seen/read. I use it in one of my Cadillacs (only because it makes me feel "good"), and in a truck manual tranny/differential.