I own a '93 GMC 250 diesel. I’ve been told it would help my fuel mileage and keep my engine cleaner if I used a fuel additive that boosts cetane. Fact or fiction? It would add to the cost of fueling my truck. Is it worth it?
If it is a product from a legit company, it won’t hurt anything, but there is no reason that cetane improver should keep your engine cleaner, and I would be quite surprised if it gives a measurable increase in mileage.
I would presume that the argument for cetane improvers would be to extend the life of the engine. That might be true if the fuel you are using does not meet the cetane recomendation of the manufacturer.
The only time I have seen cetane be a problem is when people burn jet kerosene in diesel engines. That can be a little hard on some engines, but not a big problem. The military does it routinely.
Diesel fuel is highly regulated. It has all the additives and sufficient cetane for most all car/truck engines. Cetane additives can increase mileage, but usually not enough to pay for the cost of the additive.
I suggest, and do, buy a bottle of Diesel Fuel Supplement? +Cetane Boost each fall and keep it handy for that first really cold temperature. Not all stations get winterized fuel in time for the weather, so it provides for that and at the same you you can judge for yourself if it is doing you any good.
Note, most people who believe it will increase mileage and power will feel the power increase and are more likely to see a mileage increase.