I have been running performance formula in the truck now for about the last 10 tank fills. Driving habits are the same and I see NO difference at all in performance or MPG's. This truck is still running about 13.5 MPG. out of the 40 miles per day 60 percent is highway at about 70 MPH. Has any one else seen this in these trucks

I have used it everyother tankful since almost day one of my LBZ and "on occassion" I have seen some improvements. Having said that though I'm always going to use it especially in the winter. I bought 2 cases and it has almost lasted me 2 years.

Moved to Maintenance/Fluids. ;) You will get better responses there.

I've run additives every tank since new so I really can't tell if it helps or not. It's just peace of mind for me especially in the winter.

I get 18 mpg on my daily commute which is 60% two-lane roads. I get 20 mpg easily on the highway and around 11 mpg towing 10K. The truck has been the same since it was new regardless of the mods in my sig.

Stanadyne is the only approved fuel enhancer if you want to call it that. That GM aproves of using in the Duramax motor.

I have been running performance formula in the truck now for about the last 10 tank fills. Driving habits are the same and I see NO difference at all in performance or MPG's. This truck is still running about 13.5 MPG. out of the 40 miles per day 60 percent is highway at about 70 MPH. Has any one else seen this in these trucks

You will get better mileage when your broken in. I am not sure of your miles on the odometer. Also, it is widely known that the go pedal is a better way to get better fuel mileage. For an experiment, try and go about 63mph on the stock speedometer, and see how you make out. Be sure to report back so we know. Also, try a tuner set to a moderate power level, along with the fuel supplement, and I think you will get better results. The Stanadyne will keep your injectors happier, along with keeping them cleaner!

I think some of the mileage claims are a bit far fetched, but not just on Stanadyn, but all the additive.

However, I DO believe they are a good idea regarding conditioning the fuel for lubricity and such. I run Power Service, but I'll agree that Stanadyne is a top notch product.

I bought just 1 bottle to test it. I never zeroed out the meter on the dash.
Within about 5 miles watching this meter I ended up getting 6/10 mpg more. So it will more than pay for itself.
I really liked watching that meter going up. It was almost instantly.
I was going to try Lucas next.
Some folks like that stuff from Wal-Mart.
Lee

i have been using Stanadyne Lubricity formula for a while now. didn't really see anything on the mpg front, but the truck runs smoother and quieter with the Lubricity additive. i just started using Opti-Lube XPD. i'm on the first tank using the XPD. i noticed a difference in how the truck runs but too early to say.

Has anybody done a comparison of Stanadyne vs Power Service (Diesel Kleen)? I haven't seen Stanadyne for sale around here, but Power Service is widely available in my area.

I use Stanadyne Performance Formula off and on. Off only because I run out of it.

I do notice about a 1 mpg improvement when I run it. It usually takes 2 to 3 tanks to get the truck back up to 16.5mpg after a dry spell. Why it takes that long to increase is beyond me. :confused: But true over the last 10 tries or so of being off then on again.

I'm always haulin 1000 pounds of weight so I drive conservatively at 60 on the freeway to keep way under 2000 rpm.. BIG difference in mileage!