[101Volts]

Vehicle: 1999 Chevrolet Suburban K2500 Turbo Diesel

Mods: Cold Air Intake, 80 PSI in front tires, roof rack delete, air dam, use of block heater to start at 116 fWT at crank-over*, 0w40 Shell T6 oil, Amsoil Severe Gear 75w90 in Differentials, Scangauge II.

The SGII isn't calibrated correctly and is optimistic but since the first time I drove on the same roads** I've increased the average rating from higher 20s and a touch above 30 to 37.x by the time I turned the vehicle off. A little adjustment to my mentality of this made a difference: I was often driving slow, making sure the MPGs read higher then I considered normal and traffic was light or non-existent this time. I reached above 30 AVG before I turned on the 4 mile stretch where I got up to 40 but then had a stop sign and right turn. Somehow I didn't think making the instant meter read high more frequently made this much of a difference but it does and quick accelerating from 30 MPH to 40 in the 2k-2.5k RPM range in Overdrive doesn't effect the average MPG rating a lot.

As for the actual MPGs I got they're probably closer to higher 20s or 30 than 37.x by the time I turned off the engine. I haven't tracked from fillup to fillup but the actual F.E. did seem to be getting around 20 when judging by the needle while the SGII read 25-27 AVG.

Edit -

* on this particular trip. The actual starting temperature varies depending on the ambient temperature and in my experience the block heater is good for around 50 degrees above ambient temperature, give or take a few degrees.

** "The same roads" meaning that I was going the same exact trip from my house to one particular destination; 6 to 7 miles down the road from me then on a side road for 4 miles then under 1 mile to the stop point. This does not speak for all the roads I drive on although I've learned something significant from this one trip!