hey guys just started using stanadyne perfomance formula... after 2 tanks iv lost about 2mpg hand calculated, im driving the same way same roads... right when i started using the additive i changed to a new oem fuel filter...

any thoughts on why this is happening, thought this additive would help with mpg

hey guys just started using stanadyne perfomance formula... after 2 tanks iv lost about 2mpg hand calculated, im driving the same way same roads... right when i started using the additive i changed to a new oem fuel filter...

any thoughts on why this is happening, thought this additive would help with mpg


Weird! It improved my mileage when I started using Stanadyne Jr. Were u running a different type of fuel?

nope fueled up at the same shell station diesel #2

hey guys just started using stanadyne perfomance formula... after 2 tanks iv lost about 2mpg hand calculated, im driving the same way same roads... right when i started using the additive i changed to a new oem fuel filter...

any thoughts on why this is happening, thought this additive would help with mpg


Mine also went up about 1 to 1.5 miles per gallon after adding Stanadyne, hand calculated. Took a short road trip a month ago with 6 people in the truck, cruise set on 65 mph and got 22.8 mpg, hand calculated.
Stanadyne goes in at every fill.......................................... :D

wierd maybe bad additive?? bought it from amazon, midwest fuel injection

how many miles on before using the additive?

maybe... and this is a long shot I'll agree... but maybe you're cleaning out some fuel system "gunk"?

As with the other two posters, I've gained mpg's using Stanadyne, that or Biodiesel goes in every single tank, every time.

31,000 miles before stanadayne was used

Mine went up also.

hey guys just started using stanadyne perfomance formula... after 2 tanks iv lost about 2mpg hand calculated, im driving the same way same roads... right when i started using the additive i changed to a new oem fuel filter...

any thoughts on why this is happening, thought this additive would help with mpg

How much additive are you using per tank? Do you have the 26 gal tank? I run 8 oz. per 26 gal tank, and have also observed higher mpg's. All through the winter, I did not get lower than 16 mpg. On a long haul, all highway, cruise set on 65, I get 23 mpg. You may try and change the fuel filter and see if that helps, if not, I am at a loss. Maybe the Shell station got a bad batch of fuel.

How much additive are you using per tank? Do you have the 26 gal tank? I run 8 oz. per 26 gal tank, and have also observed higher mpg's. All through the winter, I did not get lower than 16 mpg. On a long haul, all highway, cruise set on 65, I get 23 mpg. You may try and change the fuel filter and see if that helps, if not, I am at a loss. Maybe the Shell station got a bad batch of fuel.


Thats what my guess is to. Or maybe the shell station that u are at is switching from their winter blend to summer blend diesel??? That may have a small effect. Try getting fuel at a different station (truck-stop) then run they stanadyne in recommended amount and see if that makes a different.

Got 22.8 MPG (speeds from 55 to 65 on level ground) hand calculated last December using Stanadyne. Don't think it has hurt my mileage at all.

after 31,000 miles I'd lay very good money on the Stanadyne cleaning your fuel system, your new fuel filter is simply doing it's job and stopping the contaminates built up over the miles from entering your fuel injection system.

As with the others I'd suggest replacing your fuel filter, and I'll add I'd have an additional spare on hand just in case. I'd also suggest continuing to run Stanadyne (or any other branded fuel supplement) to keep your injectors lubed and clean. The new ULSD is proving to be hard on newer diesel injection systems.

got 1.5 to 2 mpg better with stanadyne, cab and chassis hauling heavy.

well went out to laughlin this past weekend put stanadyne in the tank with "truck stop fuel" same results, mpg dropped from before... on the way home stopped using stanadayne and the milage went back up WIERD... i stopped using stanadyne..

should i continue to use the addtive!?!? maybe its cleanin idkk..

using 8 oz per tank when i do use it.... is my fuel system that dirty??

using 8 oz per tank when i do use it.... is my fuel system that dirty??

I'll admit you've got me puzzled. Your observations are opposite of what is being reported by other owners and of what's expected. While it's certainly possible to get a bad batch of fuel, I'd also have to guess it's possible to get a bad batch of additive. Have you tried using any other brands of additive? Most truck stops carry Howes, Lucas or Schaffers, and if you've got one your local Wal*Mart should have PowerService. All are used by many members of this site, and again most owners report some improvement in mileage from running an additive.


I'd honestly suggest looking for another brand of fuel additive to see if your truck behaves the same way, if it does I'd personally be worried that my rig was behaving in exactly the opposite way it's supposed to when running an additive. If you get an improvement with another brand, I'd have to go with the idea that you possibly have a bad batch of Stanadyne. If you do choose to investigate whether or not your truck will run differently with another brand of additive, ensure the brand you choose does NOT contain alcohol, some do so be wary.


Keep us posted on your findings!

my mileage has gone down as well, hard to say if the 900 other bells and whistles you guys talked me into buying did it or if it's the stanadyne :D

my mileage has gone down as well, hard to say if the 900 other bells and whistles you guys talked me into buying did it or if it's the stanadyne :D


LOL.. ahhh the DP corrupts... err ahem.. I mean IMPROVES another owner :D

I broke about even on mileage after trying Stanadyne. About a year or so ago a local injection pump repair shop told me to give Lucas UCL a try and all I can say is this stuff is no snake oil. I was never a fan of Lucas products but this stuff definitely increased my mileage and engine smoothness. A product that works as advertised IMO.

Mine went up also.

x2

i usually add stanadyne at everyfill up, but the last 2 i havnt added anything just to see if theres any differince, i think i lost a couple mpg. im gonan try power service just to compare also