I'd love to see the RP/Amsoil comparisson as well.

 

I've used RP for a while now and I've been quite pleased with it. It's hard to tell any performance gains at all by using premium synthetics, but it definitely protects internals much better than conventional. Fred (RP CEO) is a friend/customer of mine and I've been very pleased with what I've seen so far.

One thing I might add, at every tradeshow I've been a part of there's always the creepy/weird Amsoil rep. I've never met a normal one, but I'm sure there's a few out there

 

I had an used oil analysis done on my wife's C240 recently. I was running Amsoil 5w40 European AFL. The car had 68000km (42500 miles) on it and the service interval was 16000km (10000 miles). The comment from the analyst (Terry Dyson a well respected tribologist) was to change the oil yesterday.

I am trying Renewable Lubricants biobased 0w20 in the truck and 5w40 in the MB. The MB is being traded so I guess I will never know the result of that. The truck will have an analysis done soon on the new engine so the results will be interesting and the risk of running a long fill reduced. The engine is new and was broken in on Castrol GTX 5W30 for 1841 km (1150 miles) after a short run of some cheaper oil fill. There is some info on this oil at Bob is the Oil Guy site as well.

Just a FYI on another oil as if there is not enough oils to consider already...LOL

 

Very interesting....the name Terry Dyson sounds familiar, has he posted oil analysis results on the net or something?

What brand of oil filter were you using, and do you have the results of the test that you could post up? Thanks

 

For info on Terry check out Bob is the Oil Guy site or Dyson Analysis. Terry takes UOA reports and provides an interpretation of the results.

On the MB I was using the OEM filter from MB and the FSS system to time my oil change and service. The car used absolutely no make up oil. I do have the report and I will try to post it latter. This was the third fill with Amsoil. The first I used Series 2000 0W30 at 18665 km (11666 miles), followed by two fills of European 5W40 at 35384 km (22115 miles) and 51337 km (32086 miles). I have UOA for all three and I will try to post them up for you later.

I tried uploading an image to Photobucket but I seem to be having a problem so that it is legible. I will try later.

 

Bob is the Oil Guy, that must be where I saw his name

 

Hi Bud, here is a copy of the last UOA. Sorry it took me a while to get back to this.

 

Here is a summary of the rest of the UOA. The first one with the ??? for the Oil Mfr. was the factory fill. The next Amsoil Series 2000 0W30 and then the first fill of Amsoil European 5W40. The Amsoil 2000 0W30 seems a match for the factory fill but with less miles on the oil. The European 5W40 was less satisfactory with a lower TBN and viscosity breakdown.

 

amsoil's warehouse and corporate HQ is in town here and you should see the winners there

 

Good info, thanks Mort