Mileage for a mechanical 6.5 Suburban 2500.

[DickWells]

Been a long while since I've paid any attention to my fuel mileage with the Burb, especially, unladen. Around here, we most often have a single axle utility trailer behind us, with anywhere from a couple-hunred to 1500+ lbs on it. ~40 miles, round-trip is average. Been seeing right around 15 mpg. I've considered that as pretty good, since we are in 1st gear most of the time, out and back in, on the two-mile Goat Path, pluss, city driving in either Show Low, Taylor, Snowflake; sometimes, all three.

Well, during our trip to Phoenix and back, I had the chance to fill it up on level ground, let the nozzle click off 3 times with the same insertion. The result was 17.73 mpg. That was for close to 400 miles, with (probably) something near 1.25 hours of city driving in Phoenix and avg 60 mph of fairly mountainous driving. Is that what others who are driving mechanically pumped 6.5's experience?

[DieselDavy]

With all of the "city" driving you did, it seems about right to me.
d

[Robyn]

Those numbers are right in the ball park with Suburbans we have had.
Best we ever saw with our 1994 6.5 (DS4 PUMP) was 18 mpg

[DickWells]

Thanks, Robyn and DD.
The old gal was a delight, for the whole trip to Phoenix and back. Had a bit of sinking "pit of the stomach", when we got stopped in traffic and the AC started blowing warm air. Thought I was gonna need to go and buy a kit. But, soon as the rpms got over a thousand, we had cold air. Happened several times, that afternoon. I have a kit, here at home,and will be hooking on and checking the AC out, but it worked well, ever since we left Phoenix. Well, the temp was 114 F in that fair city and I'll wager that we weren't the only people there with low output at low rpms.
I wouldn't live down there for any amount of money.

It's a rare day that there isn't a traffic fatality, or murder in that area. It isn't at all rare, to have both, on the morning news. Right now, there are high heat warnings and many hiking trails are closed. Camelback has been closed for days, but there have been chopper recuse done, two days in a row, for people out there hiking against the orders. I wonder if there are fines aplied? Those choppers and crews don't run cost-free.

[arveetek]

My electronic 6.5L in my 2 door Tahoe averages 16-17 mpg. Best tank ever was 19.5 mpg.

I have family born and raised here in SW Missouri. They moved to Phoenix for several years. After my cousin and his son witnessed a murder during daylight hours on the street, they decided it was time to move back to Missouri!

Casey

[Robyn]

Dick
At those high ambient temps the R134 AC systems can tend to be a little tough to keep super cold air at low RPM

You may well need to "Top up" the refrigerant charge a bit.
With the charge a tad on the low side it can result in less than optimal liquid refrigerant coming through the orifice tube into the evaporator...

The old R12 systems were far more forgiving and could produce colder air into the cab ....

R134 is sketchy at best.......With all systems at spec, they are decent....But once the charge drops off a little (All automotive AC systems leak) A small amount, but over a year or so they will lose enough to effect the performance....AND 114 F will seriously tax any system, even one in top shape....

Glad your system did the job for you....