Originally Posted by NitroVein

I would say a good 99.9% of the people adding castor oil to an existing fuel do so because it's common practice, not because they have tested it, as it's used the same way with any fuel.
Onroad is also very different from anything else for Several reasons, one of them is how they stress their engines, it's not about getting 10 gallons out of it but keeping it in one piece and castor is great for that. At the big races they can go through several engines during a weekend (at least they did, not sure if rules has changed that).

Originally Posted by SlowLST2

I see several points got lost in translation..

Working within the limits means not pushing it so far that it unzips and you end up with a thermal/lubrication runaway. I don’t need to destroy an engine to find out what a PAG synthetic will do if pushed too far. That’s well known. Castor is no different, neither is any other Pxx type of oil. Every oil has a thermal limit to which it still lubricates versus burning and creating power.

Anyway, moving along........

Originally Posted by SlowLST2

After thinking about it more, most of what’s been said here is pertinent to the thread in one way or another. People add oil to their fuel - regardless of why - and it seems to work well when castor is used. There are suitable synthetics that could be used instead of Castor, but nobody has yet to divulge what the more suitable substitutes are. Most of the common everyday synthetics are rubbish generally, but people have used them for eons without any or much issue. People sneered at me when I talked about using automotive PAG 100 and PAG 150 oil from the auto parts store leftover from when I changed AC compressors in my 1:1 vehicles. It mixed with the fuel and ran as fine as the other synthetics I’ve used.

So at the end of it, please share what synthetics you actually USE and why you use it.

Originally Posted by Roelof

Do not forget that todays sponsoring deals are not that big as in the early days. Several topdrivers just get 2 or 3 engines and maybe 1 or 2 more when there is a big event like the worlds. That will make such drivers more carefull with their engines like adding an extra drop of castor, for sure when they know their sponsored fuel has a low oil content (lower than the consumer version).
And we all know a lot of people are fans of such topdrivers, they follow them in everything they do. So if their icon is putting a drop of oil in the fuel and winning races then the fanbase will do that also.

Regarding the amount of engines. Yes, I have runned 2 worlds where 3 engines max could be used, they were marked. I do not know how it is today.

Originally Posted by Roelof

I even know a driver that sells his sponsored fuel and puts Runnertime in one of his cans of his fuel sponsor. How about fooling the customers.....

The blends I have raced with:

- 3% Castrol M50 (now known as Racing-M) combined with 6% Castrol MSSR (both are hard to find)
- 9% Euro Racing 1 (in hot weather perfect, in cold it will give a performance loss)
- 10% Shell Advance Racing M (very thin so need to turn in the needles and will give a very black engine)
- 3% Eurol Racing 1 combined with 6% Eurol Racing RX (perfect combination for a good performance and lifespan)

Originally Posted by Roelof

I even know a driver that sells his sponsored fuel and puts Runnertime in one of his cans of his fuel sponsor. How about fooling the customers.....

The blends I have raced with:

- 3% Castrol M50 (now known as Racing-M) combined with 6% Castrol MSSR (both are hard to find)
- 9% Euro Racing 1 (in hot weather perfect, in cold it will give a performance loss)
- 10% Shell Advance Racing M (very thin so need to turn in the needles and will give a very black engine)
- 3% Eurol Racing 1 combined with 6% Eurol Racing RX (perfect combination for a good performance and lifespan)