Octane boost vs. Cetane boost addatives question

I am very new to the TDI world and am researching what we could add to the fuel to increase Cetane rating of the fuel. In my experience with gas cars, the over the counter octane boosters were pretty much over priced junk. The thing that really woked was Toluene which one could obtain at Sherwin williams. Toluene is already in gasoline and as long as it has nothing else in it (No acetone!) just 2 gallons a tank would raise 91 octane to 94, which increased power noticably on cars that can automatically advance timing. I am wondering if there is a chemical that can be added to our TDI's that would accomplish the same thing. Thanks!

I have always used Power Service (silver bottle summer,, white winter).
The times that I have forgot and not used it I can tell, but most Gear Heads could.

The points on bottles of gas octane booster is not the same points as the octane on the pump, as I recall its takes six points of octane booster to make one octane point of pump gas.

Octane and Cetane are VERY different things (they are actually almost opposites). There are a variety of commercial additives that boost Cetane and other properties of diesel fuel. There are already lots of threads here about additives, so we don't need to start another "my additive is better than your additive" discussion. The general consensus seems to be tha a little cetane boost can't hurt, but most good diesel is high enough to work. However, there has been a lot of discussion about the lack of lubricity in US ULSD. If you are considering additives, read the threads about it and perhaps consider additives more on a lubricity basis rather than on cetane number alone.

http://forums.tdiclub.com/showthread.php?t=266407
http://forums.tdiclub.com/showthread.php?t=269718
http://forums.tdiclub.com/showthread.php?t=188203

Welcome aboard, as you can see there is lots of information and lots of opinions here at TDIClub. Have fun learning!

Don

One thing I forgot to point out is that I live in Southern Colorado. The fuel stations here are Sinclair, Shell and Conoco. There is no Chevron or BP Amoco. According to the improving fuel economy post one of those stations offer a Cetane of 49 which is what is recommended for our cars. This is why I was concerned about unconventional addetives that increase cetane.

Don't worry about what may be added to the diesel before you get it. Likely most if not all your stations are supplied by the same single supplier, so what comes out of one pump is the same as comes out of one across the street.

With gasoline, once you get to the an octane equal or greater than recommended, there is little or nothing to be gained by going higher, unless you modify your engine. With diesels it is almost the same, but IMO you have a little bit more to gain with higher cetane, but not enough to justify much additional cost IMO.

Good Luck and welcome.

The way I see it, it's a lot easier to lower the kindling point of fuel than it is to raise it. To lower the autoignition point you just need a pilot fuel mixed with the bulk of the fuel charge. This fuel will ignite sooner and proceed to light the main charge.

A chain is only as strong as its weakest link. So a pilot fuel (of higher cetane rating) can be used to hasten ignition of the charge whereas the entire amount of fuel would need to have a higher autoignition point for it to have a higher octane rating.

lovesTDI said:

One thing I forgot to point out is that I live in Southern Colorado. The fuel stations here are Sinclair, Shell and Conoco. There is no Chevron or BP Amoco. According to the improving fuel economy post one of those stations offer a Cetane of 49 which is what is recommended for our cars. This is why I was concerned about unconventional addetives that increase cetane.

Click to expand...

If you can find fuel better than the 40 cetane crap, get it. Your mileage and your start ups will be better.