cetane booster...and some equivalent for gas engines?
 

So I have a friend with a VW TDI, who routinely uses cetane booster in every tank and consistently sees a 15% gain in MPG from using cetane booster vs not using it.

My question is whether there is any sort of gas additives that can be added to regular gas (87), that would improve fuel economy as well? Obviously, octane booster will not help, but are there any particular additives? This assumes the car has all maintenance up to date.

No.

-soD

cetane is the opposite of octane. Higher cetane means the fuel burns faster.

He could get the same results by advancing his ignition timing. if he is seeing that much change, then his engine is messed up somehow.

to get the same, run the lowest octane gasoline you can find.

Those boosters are snake oil. They claim to boost octane or cetane by 10 points or more. One would think that means from 93>103. False. If you look at the label then you would see that one point is defined as 1/100 of the (Ron+mon)/2 values that you see at the pump in the US. So 10 points moves it from 93 to 93.1.

Running kerosene/diesel 1/jet A can make an impact on the engine. Those are winter fuels that are supposed to burn colder. Much more impact than a booster of any kind.

Impressive claim.

Can he back it up, and also tell us what and how much he's using ?

Cetane boosters are only meant to be added to low quality diesel.

yeah, i should try and get him on here. It's an '09 TDI and he drives all highway, and regularly gets 52-55mpg a tank. The few times he has run without the cetane, his tank has averaged 46mpg on the exact same routes.

When I saw him doing it (he has a big jug of it at home and just uses a syringe of it for every tank), I asked about it, and for some reason I remember him stating it is very helpful given the turbo charged engine--he is also running a ram-air intake and has modified the exhaust.

I'll ask what exactly he uses.

the additive he uses is Diesel Kleen by Power Services.

he uses 1 oz per 3 gallons.

I'll post a link in my next post since I need 5 posts to do so

I have been using diesel fuel as octane booster. The MSDS for octane booster states it is 99% kerosene anyways.

Diesel has a very low "octane" (RON rating) so you're actually lowering your fuel's resistance to combustion, rather than raising it.

This should not affect mileage though, and if it does, you're in need of a tuneup.