Don Terrill’s Speed-Talk

I am looking for more information on the difference between group 4 and group 5 base stock oils. As I understand it, the group 5 based oils (or a blend thereof) offer superior wear resistance at high oil temps. I also understand that there are not many oil companies that use group 5 base stocks (Redline, Mutol, any others???). Does anyone have a source for more information on this topic?

I thought group 4 base stocks were the synthetics and group 5 esters , silicones and other stuff not included in the base 1-3 group. Mostly base 5 gets added to other base stocks to obtain certain properties for compressors oils and such.

This is why I am looking for more information on this topic. However, I can say that I spoke with a tech at Redline and he noted that Redline uses group 5 base stocks. I have also seen elsewhere that "no oil company uses more than 40% of a group 5" in their mix. LAT has posted on their website that they use a blend of group 4 (group "VI" actually, but I assume that this is a misprint) and group 5 base stocks in their racing oils. As I understand it, the group 4 base stocks are super refined mineral oils (also known as PAO's), whereas the group 5 base stocks are actually lab made oils from alcohol and acids. If anyone knows where I can find any additional information that would be appreciated.

https://en.wikipedia.org/wiki/Motor_oil

http://www.upmpg.com/tech_articles/motoroil_viscosity/

http://www.penriteoil.com.au/assets/pdf ... e_Oils.pdf

Back when I was an Amsoil dealer in the 70's all of their oil was group 5... Castrol won a lawsuit allowing group 4 oils to be called synthetic...

Snake oil?

Krooser wrote:Back when I was an Amsoil dealer in the 70's all of their oil was group 5... Castrol won a lawsuit allowing group 4 oils to be called synthetic...

my amsoil dealer has in the past informed me that amsoil uses group 5 base stock in their race oils including dominator series and some others. and as well explained to me the synthetic scam where like a loaf of bread can be advertized as whole wheat as long as it contains a small percentage of all the components of wheat. synthetic, they are allowed to call it synthetic oil. As long as it contains some percentage of synthetic oil. So if you see a deal on some generic sythetic oil for 5 bucks a bottle. you can rest assured your probably paying to much for contaminated mineral oil.

There are almost as many discussions about this over at bobistheoilguy.com as there are torque vs HP discussions here.