I would go with a MM3 and a custom tune over a Touch any day. Custom tuning is much better than a box tune.
He can search that magical fuel economy with hard parts but it's unlikely to ever pay for itself. Driving habits and lying are the two best ways to improve fuel economy.
At what speeds were you getting 26/27 mpg? 45? downhill? 2wd? Hand calc or overhead?
26/27 isn't realistic, not even on a well modded 03/04. I had all the mods needed for a very fuel efficient 5.9 (cam, turbo, pistons, injectors, tuning, NV5600, spin free hubs, etc) and it still wouldn't consistently break 20 let alone 25. Best part is my bone stock '18 can get better mileage at 65, but it also can get slightly worse towing.
Over a 50,000-mile period. I’ve been posting this ten years now.
In order of importance (per Cummins or Kenworth; applicable to any vehicle):
1). Vehicle Spec. Like by line
2). Climate
3) Terrain
4). Operator Motivation
The above found that
with no changes except driver big truck fuel mileage can improve by .33 between best & worst.
A). What’s the best spec 3rd Gen?
B). What’s best climate, terrain; etc?
C).
What do drivers better than you know and put into practice?
The first two are obvious. The last, isn't. For me it sure doesn’t involve any stunt driving or that which places safety second
I’m NOT EVEN CLOSE to the Cummins engineer who pulled out all the stops to see better than 47-mpg. Repeatedly.
All of which is why I emphasize
finding out what the truck can do in a test your 17-year-old granddaughter can perform for you.
Empty the truck of EVERYTHING that doesn’t stay aboard every single mile.
Take the driver OUT of the equation. A 200-mile roundtrip to the sane fuel pump, and — for the second time — top the tank to the FIRST auto-shutoff.
Do that test after recording cold tire temps. And driving AT LEAST 50-miles to bring tires to equalization. Which completes warmup. Then to the truck stop fuel pump. Then immediately onto the CAT Scale.
Adjust tires to spec. Minimum. Per tire manufacturers Load & Pressure Table but INSIDE truck manufacturers range.
Make that ideal with scale weighing #2 & 3 by placing port then starboard tires barely OFF scale. Each axle load is to HEAVIEST wheel value.
This is after ALL book maintenance to date less 10%.
Get the tickets, adjust pressure versus cold readings, and hit the on-ramp. Set cruise at 58-mph. At near 100-mile mark (or farther), use an otherwise deserted crossover for return trip.
Return to same pump and refill same way
It does NOT matter how you drive other days. This is a test. A baseline.
Warm weather. No high winds. Low traffic volume.
No lane changes. No idling. No braking or accelerating except as law requires.
60 is the wall. That or above is too fast to get aero resistance out of the picture. Those of us who’ve studied it will tell you the same. 58/9 is max. (Use rpm to re-set Cruise).
I bought my truck with highest MPG a priority. And had to FORMULATE A PLAN to get the most from it.
MPG is a planning tool. On those trips I saw 26-27 mpg at trips end, I learned
With truck empty (per above) or loaded 1,200-lbs above TARE and with/without changes to conditions of rain, cold temps, heavy traffic, my fuel burn didn’t fall below 24-mpg.
That 700-mile roundtrip was made several times monthly. And included crossing Houston twice per round trip.
The number for planning I found. Under those conditions of CLIMATE & TERRAIN. With that SPEC of truck. With DRIVER MOTIVATION.
Reduced speed is the rookie. There’s much more to high mpg where the base is lane-center, steady-state on cruise-control
. One learns to count the tenths. Use the overhead readout to SEE changes.
EVERYTHING is open to change.
Feelz are for girls and kids. The way YOU drive.
And it always comes down to a plan. Time of departure. Every stop known in advance. The legs of the plan are what one drives. Separately.
How fast one gets anywhere is for the stoopid. Buy a police-spec Charger you want a high average MPH.
The relation between Average MPH and Average MPG is how I
know the truck and driver are in synch. Driver and truck operating without problems. No defects.
But it takes a good while to get there. Doing it without any effort.
My truck can’t reliably hit 26-27/mpg? How about I show you I can repeatedly hit 28-30? Dead stock. At TARE. Just set the cruise.
This stuff ain’t rocket science. It’s application and discipline. What men do.
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