Article: pickup mileage - manufacturers are ecomodding their trucks for better MPG

[MetroMPG]

The Trucktrend web site has posted a fairly interesting/comprehensive article about what steps manufacturers are taking to squeeze more MPG from recent pickups in response to customer demand, the threat of rising fuel prices, and tightening fuel economy rules.



Let's get this out of the way first: the title - "Good to the Last Drop: Getting the Most Possible Mileage Out of a Pickup" - is ridiculous, of course. Obviously they're not getting the best possible mileage. Truck makers are notoriously conservative, and the spectre/excuse of "consumer acceptance" plus fear of halting/reducing the ever-increasing towing/payload specs keeps them from doing anything beyond incremental changes.

But the article does cover a wide range of tweaks, and interestingly it quantifies many of them in terms of effect on MPG.

Weight reduction:

• aluminum lower front control arms and 17-inch aluminum wheels on the GM XFE trucks
• GM says "about a 0.7-mpg (EPA combined) benefit per 500 pounds in weight savings."
• Toyota says: "A 50-pound weight reduction is worth about one percent in fuel economy."
• Nissan says: "Reducing its weight by 100 kilograms (220 pounds) can boost economy by about 1.5 percent"

I wonder why the formulas disagree. I suspect it's the way the article was written (no context - city? hwy? combined?), rather than fundamental differences between the companies.

Improved aero:

• better initial design, aided by CFD and wind tunnel testing
• GM’s XFE pickups have lowered suspension, bigger front air dams, and OEM tonneau covers - " the tonneau cover gives a 0.1- to 0.2-mpg improvement, the air dam maybe 0.05 mpg, and the slightly lowered suspension another 0.05 mpg. "
• Ford: "aerodynamic improvements on the 2009 F-150s average around 15 counts, or 0.015 Cd. “That 15-count improvement gets you on the order of 0.12 mpg highway"

It's funny that each of the Big 3 manufacturers claims "best" drag coefficient for at least one of its pickup models (depending on style, eg. whether it's a crew cab, long box, short box etc.).

Nissan's engineer comes across as the most pessimistic of the lot:

“But a 10-percent [aero] drag reduction is almost nonachievable,” he adds. “That is drastically changing the style of the body. In the real world, two or three percent is really tough for us. And 100 kilograms of weight is almost a hopeless number. That is almost downsizing the truck, which is really tough. Honestly, 1 mpg is a huge number for me.”

Engine mechanical & calibration:

• DCFO WTF?? Am I reading this right - is deceleration fuel cut-off (DFCO) really a NEW feature in some truck engines?? "Ford F-150: Among these are such fuel-saving features as open valve injection and deceleration fuel cutoff on 4.6- and 5.4-liter V-8s."
• Also in the Ford: "a substantial 0.5-mpg gain comes from lowering engine idle speeds by about 100 rpm"
• Dodge added variable valve timing to the available 5.7-liter Hemi V-8 engine, which already had Chrysler’s cylinder-deactivating Multi Displacement System. All this achieved an average 1-mpg improvement over 2008 models
• Toyota's variable valve timing reduces part-load pumping losses
• Nissan: friction-reducing measures as piston ring coating and camshaft microfinishing

Engine accessory:

• Ford: high-efficiency alternators
• Ford: changed pulley ratios on power steering pumps, and changed water pumps in the engine to make them more efficient

Transmissions & final drives:

• taller rear axle final drives all around
• six-speed transmissions: "the F-150’s new six-speed automatic contributes roughly a 0.25-mpg improvement"
• Nissan mentions a CVT

LRR tires

• Several trucks use them, and Nissan says: "Reducing rolling resistance by 10 percent can get you 0.2-0.3 percent better economy."

Full article: Good to the Last Drop: Getting the Most Possible Mileage Out of a Pickup - Consumer Feature - Truck Trend

[Daox]

Haha, I like the first comment:

I have often wondered by designers make trucks, especially the F series and Silverado, resemble bricks. Its time for a little more imangination in pickup exterior design. They should not look like a Prius, but why do they have to look like something a child designed?

Quite true.

[MetroMPG]

I noticed that one too. Also, that Nissan engineer's attitude is disappointing.

[tasdrouille]

“But a 10-percent [aero] drag reduction is almost nonachievable,” he adds. “That is drastically changing the style of the body. In the real world, two or three percent is really tough for us. And 100 kilograms of weight is almost a hopeless number. That is almost downsizing the truck, which is really tough. Honestly, 1 mpg is a huge number for me.”

Gee, I have a hard time recognizing what type of vehicle that is.

[tjts1]

Here is a thought. Don't buy a giant 3+ ton truck. Just imagine how much fuel you'll save.

[Frank Lee]

Nope, nope, can't do that!

[elhigh]

Gigantic ladder frame underneath means there's an awful lot of turbulence. Did the engineers forget that the whole truck is a wetted surface?

And what about those GARGANTUAN wheel openings? That drives me crazy, there's enough height above the tire for me to be able to insert my entire head!

In my brain, the winning model is to get the biggest bed you can in combination with the smallest engine. Drive gently, as if going faster cost more. Settle for somewhat less sprightly performance when carrying heavy loads and towing.

I know, common sense and all that. And yet, precious few people buy the big box stripper model. That's a shame.

'Cause the world needs more strippers.

[chuckm]

elhigh, you know why they design them with those huge wheel openings, right? Otherwise, in the commercials when they drop that huge load of bricks in the bed from 20 feet (just like you do so often in real life), the tires don't touch the wheel well. I mean, you don't want to get the impression that your suspension will bottom out when you exit the second floor of the parking garage the fast way.

[darcane]

Originally Posted by elhigh

And what about those GARGANTUAN wheel openings? That drives me crazy, there's enough height above the tire for me to be able to insert my entire head!

On my truck, those huge wheel openings don't even have inner fenders. Air flows in and is directed right at the parachute, er.. rear bumper.

Originally Posted by elhigh

In my brain, the winning model is to get the biggest bed you can in combination with the smallest engine. Drive gently, as if going faster cost more. Settle for somewhat less sprightly performance when carrying heavy loads and towing.

I know, common sense and all that. And yet, precious few people buy the big box stripper model. That's a shame.

'Cause the world needs more strippers.

That's what I've got. Silverado W/T model with a long bed. No whiz-bang do-dads, no power locks, power windows, etc. Smallest V8 that's available (The V6 can't tow enough for my needs) and 2wd.

I would have preferred a manual and higher gears, however manuals are virtually non-existant and I got a great deal on the truck I found.

[user removed]

Something like the T100 with a 4 cylinder and a 6 speed. It would carry the regulation 4X8 sheet of plywood if memory serves me right.

regards
Mech