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Old 01-03-2020, 04:39 AM   #32 (permalink)
Master EcoModder
Join Date: May 2019
Location: California
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2020 - '08 Chevy Tahoe H
Last 3: 18.4 mpg (US)

2021 - '08 Chevy Tahoe H
90 day: 17.08 mpg (US)

2022 - '08 chevy Tahoe LT
90 day: 19.27 mpg (US)
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Originally Posted by slowmover View Post
I doubt you drive much differently empty or loaded. It’s a bad habit to change up for the temporary empty condition. No one cares about your non-revenue miles. Just the loaded ones. Same rules apply (vehicle design).

Thus (for anyone, but around here they’re not interested in economy), you’ll want to load that personal vehicle to 80% of sticker or higher. 13-weeks minimum (calendar quarter; valid habits change with zero deviation) of record-keeping.

Be a good idea to load it per above and take it out for a hard highway run. Heavier, if you can manage it (trailer for higher aero resistance). An Italian tune-up preceding a habits change is necessary.

It’s “fun” to do the Kevin Rutherford thing, so in your personal vehicle you want a feedback gauge to use. An engine hour meter, as metro driving is about

Never idling & Never Stopping

as, it’s your Average MPH that’s at stake.
Higher = Better.

When to Shift
How to Shift

will fall into the decision previously-made to emphasize engine/trans braking for that road stretch. Street type plus traffic & weather. The, “Do Not Exceed”, reference you establish. IOW, a 50-mph road on which you never exceed 45 as that’s a shift point that takes you from Direct into OD.

Then — inside of that — is finagling with some rpm changes.

Empty, anything goes. But it has no meaning. It’s Y x 0. Nice guys here, next to none are serious. The loaded tests are the baseline against an empty by which to know the percentage gap to close. One has to work the drivetrain and brakes plus steering to affect a loaded vehicles momentum in a positive manner. Penalties are immediate. (As they should be). “Empty” pickup only exists on paper, is another way to say it.

TARE, is useful, sure. So is sub-60/mph on cruise. Those numbers represent the possibilities. They just aren’t real.

IOW, the difference between Town & Country can disappear given reasonable use. I took mine to under 10%. Same 1200-lb load. (Truck in sig. Stock. Minimum-allowed tire pressure.) 24-MPG Highway. 22-MPG city.

A plan is required. UPS “No Left Turn” Routing. An errands loop where the farthest point was reached by freeway FIRST. Work back to house. Etc. Accomplish the necessary, but with lowest fuel burn and never compromising safety.

The Key: Once you know the gear choice that promotes throttle-off slowing so that you never have to come to a stop, the rest is an easily-managed daily drama. It’s acquaintance with the roads (as you already know) that make those predictions easier.

Just pretend you’re humping around town for YRC in a day-cab & pup. Just none of that heart-stopping blind-side backing, ha!

the 60MPH rule is point less depending on the vehicle a good example is going 75mph Actually uses less fuel then going 55 or 60mph

at 75mph it's 14-15mpg on the DIC reported 4th gear v8 mode

as going 60mph will drop it to 3rd gear..the DIC says 9-11mpg

ON a hilly area

if you say go slower 40-45mph on flat land will yield 31MPG in EVT mode

the Op will have to find the Sweet spot on his vehicle
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