How does 18 mpg in city driving and 25 on the highway sound for a full-size pickup? That’s what Chrysler’s Ram brand is claiming for some of its 1500 series trucks with a gutsy V-6 gasoline engine mated to an 8-speed automatic transmission.

Those kinds of mileage numbers were unheard of only a few years ago, even for pickups with hybrid powertrains.

It’s only been in recent years that pickup buyers began caring about fuel economy.

It was just presumed that lots of gasoline was part of the cost of a solid and versatile pickup. But persistently steep prices at the pump have turned around people’s thinking.

Builders are responding with advanced designs for powertrains, aerodynamics and chassis components.

Ram executives bragged about that high mpg highway number during the introduction of their 2013 Ram half-tonners last year. They compared it to lesser figures from V-6 and V-8 engines offered by rivals Ford and General Motors.

Under the hood

The Ram 1500’s gains in fuel efficiency come partly from a new 8-speed automatic transmission. It’s a first in pickups. Competitors still use only 6-speeds (as does Ram itself in some models).

Made by ZF Friedrichshafen of Germany, the 8-speed shifts early and often to keep engine revs low at any road speed, especially if a driver makes sure to use a light foot.

Ram’s calling this smooth tool the “TorqueFlite 8.” With the 8-speed comes a dash-mounted rotary shifter, with up- and downshift switches on a steering wheel spoke. These replace column- and floor-mounted levers.

The ZF tranny easily handles the 305 horsepower and 269 pounds-feet of the Pentastar V-6, whose displacement is 3.6 liters, as well as the bigger Hemi V-8, which now has the 8-speed, too.

Like the Hemi, the Pentastar boasts advances such as variable valve timing and pulse-width modulation of the alternator to reduce parasitic loads. Chrysler’s been installing the Pentastar in sedans and SUVs, and it’s gotten raves from car writers for its go-power and impressive fuel economy. It replaces a rougher-running and thirstier 3.7-liter V-6.

Taking it for a drive

The Pentastar slips easily into the big engine bay of the extensively refined (and very handsome) ’13 Ram half-ton pickup. The numbers suggest healthy propulsion and it certainly provided that without revving its heads off.

The short-bed Regular-Cab truck I drove was empty except for me and a driving partner, and I think it’d labor a bit if it were loaded or pulling a trailer weighing anywhere near its 6,500-pound tow rating. But it was way more than adequate on this drive amid rolling hills near Nashville, Tenn.

Our hosts had close to two dozen ’13-model Ram 1500s with either the V-6/TorqueFlite 8 powertrain or the 5.7-liter Hemi V-8 with the then-current 6-speed automatic. The V-6 with the 8-speed powered the Flame Red regular-cab 4x4 you see above.

I grabbed it for my initial drive because it had work-truck equipment, including a 6-foot, 4-inch-long bed with Ram Box side compartments, sprayed-in liner, and cargo-management hardware.

But in trim it was no stripper. It was an SLT with “premium” cloth seats and well-appointed plastic trim panels in black and “diesel gray” (even if the engine ran on gasoline).

Instruments were trimmed in chrome and most were easy to read, and there were four engine condition gauges (most light trucks these days offer only two).

The Uconnect electronic system had AM, FM and SiriusXM satellite reception with an 8-inch touch screen that controlled the radio and climate-control system. It sounded nice and didn’t need a nerd to operate it.

If a truck’s going to scoot around empty or lightly loaded most of the time, then the V-6 is more than adequate.

But as racers say, there’s no substitute for cubic inches, and the Hemi (with 345 of ‘em) is the better choice for its stronger feel and more leisurely operation, as well as its greater work capability (tow rating, for example, is several thousand pounds more).

The 5.7-liter V-8’s rated at 395 horsepower and 407 pounds-feet. But the Hemi, even when mated to the 8-speed autotranny, won’t be able to get the fuel mileage of the Pentastar.

The truck itself helps the mpg numbers with “active aerodynamics” – radiator shutters that close when frontal air’s not needed to cool the engine – and electric power steering, which causes less drag on the engine than a constantly running hydraulic pump, among other things.

The nose and body are said to be smoother to lower air drag. This contributes to quietness while under way, making driving a Ram 1500, even a few-frills work truck like this one, a pleasant experience.

For several model years, all Ram 1500s have come with a coil-spring/multi-link rear suspension that smooths the ride, particularly when the bed’s empty or lightly loaded.

A four-point air-bag suspension is now optional and is especially nice when traveling over bumpy surfaces, like the grassy field I traversed in a fancier Ram with a crew-cab body. Competitors offer neither of these suspension advancements, though some models have soft cab mounts that achieve similar results.

Ram has leapfrogged ahead of its competitors with the latest 1500 series. Automotive writers saw that when they posted their ballots for several recent awards: Truck of Texas, Motor Trend Truck of the Year and North American Truck of the Year.

If you’re a loyal Ford or GM guy (or favor Nissans or Toyotas, for that matter), all this is heresy.

You’ll probably feel vindicated when your builder tries to go one better with its pickup in the next year or two or three. But for now, Ram deserves those awards.