can someone verify my math please.

Uhm you can not judge from what a truck used to do unless it was you doing it. The single biggest factor in MPH is the 6 inches between the drivers ears and the connection to their right foot.

Not trying to discourage your research but only numbers with you behind the wheel should be compared. The only semi-scientific way of judging a cost benefit ratio is to do hard numbers with the additive and without it with as few variables as possible.

Possibly running one full month with the additive since you have those numbers compared to a similar temperate month without it.

 

Ran some today, seems to idle a lot smoother, other than that I dnno if its improved much. But if it helps the motor i might just keep adding it. Its only $30 a week.

 

Guys this is pretty easy.DIVIDE THE MILES DRIVEN BY THE GALLONS PURCHASED TO GET MPG.Do this over a period of time to get an accurate avg.What do you need a spreadsheet for.Its pretty simple math.

 

You're spending so much time on spreadsheets and figures that there's no time left for driving.

More driving, less Geeking.

I do a tank-to-tank mileage average too, but it only takes seconds to complete. Forget your daily or tankful average, look at the last 30 days' fuel use.

Be more concerned about throttle position, roadspeed and idle time than a spreadsheet on a monitor or you'll be unable to see the forest through the trees.

 

I dont fill my tanks so I guess im kinda not going to beable to figure out my true mpg's but it does seem to act a little better. But who knows it might be in my head. Its not easy to check my mpg because i drive stop and go alot doing short hauls.

 

Well, you could fill it full once a month and then calculate from there.
Not that hard.

And it has nothing to do with short or long hauls.

 

i use 250 gal a week so it has just too much veriables as i haul different areas durring the week and idle all day long.

 

Them short miles and high idle time, you have to save 3% mpg's just to break even on $30. Your main concern should be how to get the idle time down or everything else is redundant.

 

well if it helps the motor i dont care, its $30. I aint going to keep turning it off and on all day.