Hey guys just got a 2000 C5 with 88k on it and would like some oppinions on changing the oil with amsoil synthetic. Any one had good results with this type ? -----> appreciate any feedback =

 

I used to use it with good success, but they recently changed their formula and the viscosity at 100 degrees C has been dropped (still within the 30 weight range) so I have switched to the German Castrol.

 

Amsoil is a very good oil, although I too use German Castrol 0w30, with excellent oil analysis results.

Amsoil 5w40 would probably be the oil I would switch to if German Castrol were to disappear.

 

I use it. I have the 5-30 in now and will switch over after winter to the 10-30. Both meet GM spec 4718. I also have it in the trans and diff as well. Very pleased so far. Plus they deliver to my door.

 

Vettenuts, where are you picking up the German Castrol? How is it labeled?

Thanks.

 

Autozone, look for 0W-30 and "Made in Germany" on the back.


"Amsoil 5w40 would probably be the oil I would switch to if German Castrol were to disappear."

Since Patman has stated this, I will file it away for future reference

 

Thanks!

 

Keep it filed away in a safe place, since I've got a three year supply of green formula GC so I won't need to switch to anything just yet.

I will try the gold version of German Castrol once my green supply is gone, so far the gold version appears to be just as good as the green. But you never know when Castrol might pull the plug on that stuff and go to something completely different.

 

A fellow forum member who had been running GC 0w30 in his Vette volunteered to run the AMSOIL Series 2000 0w30 in his car to compare the two oils. The results showed the two oils performed essentially equivalently in his car. This test was run this spring and summer.

GC sample was taken on 3/11/05 with 3126 miles on the oil and 49880 miles on the engine.
AMSOIL samples were taken 5/6/05 with 3281 on the oil and 53161 on the engine, and 6/5/05 with 3513 on the oil and 56675 on the engine

GC AMS AMS
Aluminum 1 2 1
Iron 6 6 5
Copper 9 13 11
Lead 2 3 2
TBN 4.2 7.3 7.7

Note: A measure of an oil’s ability to neutralize acids is expressed by its Total Base Number (TBN). The greater the number, the greater the amount of acidic byproducts the oil can neutralize. The AMSOIL virgin oil analysis TBN was 11.9. We didn't get a virgin sample of the GC.

The above wear numbers are all about 25% of that lab's (Blackstone) universal averages for the LS motor family. Clearly both oils perform very well and which one you use probably boils down to a personal choice and where or how you prefer to buy. GC is made overseas and imported for a British company, but available in many stores. AMSOIL basestock is made by American companies and blended in Wisconsin, and is available online benefiting the forum (ordering info in my sig).

 

Thanks for that info subdriver! The only thing which concerns me is that Amsoil recently reformulated their 0w30, 5w30 and 10w30 and now they are all a bit thinner. So they don't offer the same HTHS number as before, and would most likely show slightly higher wear numbers in the LS1 (which prefers an oil which is in the range of 12 to 14 cst, so it likes a thick 30 to mid 40 weight oil the best) That's why I recommend Amsoil's 5w40 over their 30 wt viscosities in the Corvette.

 

I was a little concerned about that as well, but these samples were run after the new API SM standards went into effect and the virgin viscosity was 63.4 SUS at 210F, still near the upper end of the 30 weight band. That said, I agree with you that the AMSOIL Synthetic 5w40 European Motor Oil would be an excellent choice as well for those cars outside the warranty requirements (as it isn't listed to meet GM Standard 4718M).

 

So, is AMSOIL Synthetic 5w40 European Motor Oil better than Mobil 5W30?

 

In my opinion, it clearly is, but others will disagree. However, has I mentioned above, this oil isn't listed to meet GM Standard 4718M which is the owner's manual requirement as it is too heavy. But, for those out of warranty, I would prefer this oil as the LS1/6 seem to respond better to a heavier oil in used oil analysis reports I've seen.

 

One thing to note, the Service Manual states that ACEA A3 is an allowable substitute for GM 4718M. Does the Amsoil meet this standard? I think GM realizes all their cars are not driven in the US so they need to have an alternative.

 

I hadn't read that in the manual. Thanks for the info. The AMSOIL European 5w40 does meet ACEA A3/B3 standards.

Do you know if that is in all manuals, or only those sold in Europe? I'll have to give the manual another read through.

 

It was in the lubrication system in my 02 manual. I don't remember, but I believe the ACEA A3 requirements are more stringent than GM 4718M.

 

I have used all of the different synthetics. Amsoil is in my C5, Royal Purple was in my C4 until I recently switched to Lucas Oil, and Redline is in my C6. And I am happy with all of them. I have to say that I currently do not burn oil and the car runs great with the AMSOIL. In fact I just ran this last batch for 15,000 miles testing their 15,000 mile change recommendation. As stated I have not burned any oil in this car and do not have to ever add any oil. I am going to try their new filters this next go round. They have new oil filters that are supposed to be even better than the ones they are replacing. Supposedly what you do now is change the filter more often and let it do it's job and then top off the oil after the filter removal. This supposedly will get you to the 25,000 mile range. I'm not so sure I will go that far with my experimenting but I will test it to about 20,000. I sent off the oil from my last oil change and will analyze it and compare it once I get it back. And as stated, I have never had a problem with Amsoil. One thing I will definitely stress is to not put it in a lawn tractor though!! Ask me how I know that.

 

The new AMSOIL Ea Oil Filter is rated to match the life of the AMSOIL SAE Synthetic Motor Oils, namely 25k miles or one year for normal service, 15k miles or one year for severe service. With this new filter you don't have to change the filters more often than the oil. The EAO32 for the LS1/LS2/LS6 is supposed to be out Dec 15th.


Uh... sounds like a good story.