What is everyones oppinon on Marvel Mystery Oil. Does it help Diesel engines? Is it good used with oil or diesel fuel? I just wanted to know if there is any good to it or if anyone here uses it and if it helps with anyones vehicals.

 

It works especially with the low sulfer fuel, but it is RED same color as off road fuel which is fineable or may void your warranty if Mercedes thinks your running high sulfer off road fuel. Transmission fluid was chevrons diesel additive but is red also. There are many other good clear additives I've used Lucas with success it will even help poor grade gasoline. Main thing is your adding lubricant for the pump for long life which sulfer used to do. Some old style additives are not designed for Feb 07 and later diesels with particulant filters and could cause issues. Most of the new additives also help clean the injectors too.

 

Okay thanks guys, what is the additive to use for the fuel to not gel? And when is the best time to use it. I don't want to have it happen again. My older mercedes it got so bad I had to remove the tank and clean it.