on a recent trip on the interstate with no trailer i got 16.7mpg (via dic) with the stanadyne and 17.9mpg without. I thought it was supposed to increase the MPG?

its funny you mention this. myself and unit453 were talking about this samething last night. were the driving conditions the same. ie flat road, no hills, weather the same.

on a recent trip on the interstate with no trailer i got 16.7mpg (via dic) with the stanadyne and 17.9mpg without. I thought it was supposed to increase the MPG?

I would suggest something else changed. Maybe wind direction/speed, vehicle average speed, humidity, slope of terrain. There are so many varibles that effect our fuel mileage and it may be a combo of several diffferent things. Driving same day/same way with all things equal you should see about 1 - 1.5mpg better with Stanadyne. Was your observation made on the same stretch of road going the same direction or oppisite direction. Up hill on the way there is down hill on the way back, if you get what I mean?

I said this on other post about fuel additives for lubrication. After talking to a fuel dilivery man he informed me that there were additives put in by the petroleum companies to make up for the lubrications sulfur use to add so nothing needs to be added to the fuel. I tried a additive and saw no increase in mileage. Everyone has there own opinoin though.

From a logical/physics POV, there is no reason to believe that ANY additive will significantly increase your fuel efficiency. They will not add enough BTU's to make a difference, cannot provide enough additional lubricity to make a difference, and the volume of distribution is simply too great to expect much improvement at all. I would say save your money.

In some cases a cetane boost may slightly help milage. Basically it would be like advancing your timing a bit. Just my .02

It was the same stretch of road but in the opposite direction. It was I75 from Lexington, KY to Atlanta, GA and back so it was essentially down hill with less MPG and uphill with better MPG while stuck in NASCAR RV traffic from Bristol. I guess I will use the additive that I bought, 1/2 a case left, and call it a day or save it for winter. Most people I have talked to swear by it especially for questionable fuel and possible water.

I only use anti Gel in the winter which has lubricants in it but that is the only time I use additives.