Just curious what everybody's gauges read while running 75 mph on flat level terrain, not pulling.

My truck is an 04.5 with the 3.73 gears. The truck weighs about 8000 lbs.

My truck is turning 2000 rpms at 75 mph. Fuel pressure on stock original (engine mounted) lift pump is around 7 psi. Water temp gauge is 195-200. EGT is around 650. Turbo Boost is around 6 psi. Trans temp varies according to outside temp but is usually between 140-170 degrees and up to about 180 on a 100+ degree day.

What are your numbers? Are they similar?

 

My truck is pretty much modified, and yet your readings seem to be inline with mine. 05, 3.73 gears, 35x1250/20's tires, fuel presure 18psi ( fass 150), water temp 205*, trans 130* average, 180* at 100+ * days ( with ats deep pan), 1900 RPM at 75 mph, 2000 at 80 mph ( it loves that speed and rpm), boost 0 (silver bullet turbo), fuel mileage at 80 mph averages 18.7 mpg. 20.1 at 75 mph.

note: winter time my mileage will decrease, to 15.7-16.2 mph under the same conditions due to fact the fuel "scrinks" to the cold and expands during warm weather. You watch on the treads as the weather gets colder, people start complaining about sudden fuel mileage issues, and wonders was up with their trucks? And then when spring comes along people once again start bombing their trucks and start bragging about how their new accessories have increased fuel mileage...It just cracks me up every year

 

Boost is around 8-9 psi. FP with the stock in-tank lift pump is around 8 psi. EGT's hover around 550-600 degrees. My rpm's at 75 are at 2150. This is the stock turbo, 315's, and the bullydog on performance setting. Oh exhaust is w/kitty minus muffler and i have the stock intake and filter.

 

My truck is nearly identical to yours,& the numbers are virtually the same.I have a carter lift pump so my fuel pressure runs about 22psi.But other than that everything else is the same as yours.I'm also getting about 18.5mpg.

 

Thanks for the posts! I was pretty certain my numbers were running about average.....but I just wanted to see some other input on it.

Boz's truck sounds about right from what I know about the G56 equipped trucks, but the EGT's were just a little lower than what I would have thought particularly with the stock air box. Also, the in tank lift pump equipped trucks seem to be pushing about 1 or 2 psi higher than the engine mounted stock lift pumps. ( i noted that on a friend's 05 truck too....and now Boz's.)


Bigwheels.....wow...our trucks are just about identical. Same size tires, same air intake, gears, tranny etc. I just don't have an aftermarket fuel pump (yet). My mileage only hovers around 15-16 though. I am either in town or running about 75 down the highway. I am sure it would improve if I would slow down a little on the highway....but oh well. I wonder if the aftermarket fuel pump and increased fuel pressure effects mileage in any way?

 

I have the 6 speed with stock tires and 3.73 gear. I run 2175 at 75 MPH with boost around 8 PSI and EGT around 625-700. Water temp is suaully around 190-195. Fuel pressure is around 18.5-19 with the FASS HPFP 95.