After a significant round of improvements last year, the Ram 1500 pickup gets even better for 2014. Headlining the handful of updates this year is a new turbodiesel V6 engine. This is the only diesel engine offered in a light-duty full-size truck, and it promises impressive fuel mileage and towing capability.

One of the best things about driving the new diesel-powered 2014 Ram 1500 is that you'll barely notice any difference compared with the gasoline-powered versions in normal driving. The cabin remains peaceful, and typical of diesels, there's plenty of thrust for merging and passing, and it's accessible from low rpm.

Of course, some consumers prefer the power characteristics of a traditional gasoline V8, so Ram will also continue to offer its 5.7-liter V8 engine as an optional upgrade over the base gasoline V6 engine. The torque ratings are very similar between the diesel engine and the gas V8, but the V8 has slightly higher towing capacities (depending on the cab/bed configuration you choose), and it's actually a less expensive upgrade than the diesel. However, given that Ram expects the diesel V6 to top the base gasoline six-cylinder's EPA fuel economy ratings, the extra up-front cost for the diesel is likely to pay for itself within a couple years.

The new engine option enhances what was already a class-leading truck. The Ram 1500 has the nicest interior of any full-size pickup. Its upgraded touchscreen interface is impressively easy to use and offers substantial technology capabilities. We're also fond of the Ram as it offers a composed and smooth ride whether you're driving it on- or off-road. That's largely due to the fact that the Ram is the only truck in this class with a coil-spring rear suspension plus an optional air suspension that you can use to adjust the truck's ride height.

Of course, Ram is not the only company offering a comfortable and capable full-size truck. The 2014 Chevrolet Silverado 1500 and its more upscale twin, the GMC Sierra, offer strong gas V6 and V8 engine options, as well as comparable cabin amenities, including a slick touchscreen and voice control interface. The 2014 Toyota Tundra has received a significant interior overhaul this year and boasts a strong V8 engine of its own. Also, no search for a full-size truck would be complete without taking a look at the Ford F-150, which remains one the best all-around options in this class. In our view, though, the 2014 Ram 1500 noses out the competition in most areas -- whether you're talking ride comfort or fuel efficiency -- and remains our top pick for a light-duty full-size pickup.

The 2014 Ram 1500 is a full-size pickup available in multiple body styles. The regular cab seats three and is available with either a 6-foot-4-inch or 8-foot cargo bed. The extended cab ("Quad Cab") can seat up to six and comes only with the 6-foot-4 bed. The crew cab increases rear-seat legroom, and is available with either a 5-foot-7 or 6-foot-4 bed. There are six main trim levels: Tradesman, HFE, SLT, Sport, Laramie and Longhorn.

The workhorse Tradesman comes standard with 17-inch steel wheels, black bumpers/grille, automatic headlights, a locking tailgate, a sprayed-in bedliner, vinyl floor covering, air-conditioning, a 40/20/40-split front bench seat, vinyl upholstery, a tilt-only steering wheel, cruise control and a six-speaker sound system with auxiliary and USB inputs. Extended and crew cabs also have power windows and a folding rear bench seat.

Options for the Tradesman include various equipment groups that allow you to add keyless entry, power locks and mirrors (and power windows on regular cabs), cloth upholstery, carpeted flooring, a 5-inch touchscreen audio display, Bluetooth phone and audio connectivity, and satellite radio.

The HFE (high fuel economy) trim level (two-wheel-drive regular cab only) includes automatic engine stop-start (not available on any other trim levels), a mandatory 3.21:1 rear axle ratio (most other trims give you several rear-end gearing options) and a tonneau cover, all of which help optimize fuel economy. It has cloth upholstery and power accessories as standard, but Bluetooth remains optional.

The SLT includes all of the above amenities as standard (save for the spray-in bedliner and HFE-specific add-ons) and adds 17-inch alloy wheels, chrome exterior trim and dual gloveboxes. The optional Luxury Group adds power-folding outside mirrors (with integrated turn signals and puddle lamps), an auto-dimming rearview mirror, additional interior lighting, an overhead console (with garage opener), illuminated vanity mirrors and a leather-wrapped steering wheel with audio controls.

The Sport has all that standard, plus a tuned dual exhaust; body-colored grille/bumpers; LED running/turn signal lights; foglights; folding/auto-dimming outside mirrors (with integrated turn signals and puddle lamps); 20-inch alloy wheels; front bucket seats with a center console; a 10-way power driver seat; heated front seats and steering wheel; power-adjustable pedals; a 60/40 split for the rear bench seat; dual-zone automatic climate control; an 8.4-inch touchscreen display with a rearview camera; and the Uconnect Access system with voice control, text-to-speech messaging capability, emergency roadside assistance, streaming Internet radio (delayed availability) and 3G Wi-Fi capability (via an extra-cost contract); a 115-volt power outlet and LED cabin lighting.

The Laramie trim level (available in extended and crew cabs only) comes standard with virtually all of the Sport's features, with a few differences (such as chrome bumpers/grille, two-tone paint and a front bench seat), along with added luxuries such as heated mirrors, driver memory functions, leather front seats (vinyl in the rear), a six-way power passenger seat, wood-grain/chrome interior trim and an upgraded sound system with a subwoofer.

The Longhorn (crew cab only) adds a mesh grille insert, the spray-in bedliner, tow hooks, a larger fuel tank, a remote ignition, front/rear parking sensors, HD radio, and a navigation system with traffic updates and a Yelp-based search engine. The Limited package adds air suspension, monochromatic paint, chrome side-step bars, automatic windshield wipers, automatic high beams, keyless ignition/entry, a leather and wood steering wheel, upgraded leather upholstery, ventilated front seats and heated rear seats.

Many of the upper trim levels' features are optional on the lower trims. A variety of packages (depending on trim level) are available as well. The Lone Star (Texas only) and Big Horn (everywhere but Texas) are similar in that they bundle together a bunch of the SLT's optional equipment along with special badging and trim. The Outdoorsman (available only on four-wheel-drive trucks) includes gray bumpers, a larger gas tank, underbody skid plates, tow hooks, all-terrain tires, a limited-slip rear differential, cloth bucket seats with console, two-tone paint and fender flares. Other notable stand-alone options include an air suspension (optional for extended and crew cab models only), integrated weatherproof bins (called RamBox) and an integrated trailer-brake controller.

Standard on the Tradesman, HFE and SLT is a 3.6-liter gasoline V6 engine, generating 305 horsepower and 269 pound-feet of torque. The V6 is matched to a standard eight-speed automatic transmission. Rather than a traditional shift lever, the eight-speed is controlled by a rotary "e-shift" knob on the instrument panel, which frees up storage space in the Rams with center consoles. Two-wheel or four-wheel drive is available. There are two 4WD systems: Both have a low-range transfer case, but one is a traditional part-time system, while the other is more deluxe with an on-demand Auto 4WD mode.

With the standard V6, the 2014 Ram 1500 boasts EPA-estimated fuel economy of 20 mpg combined (17 mpg city/25 mpg highway) with two-wheel drive. EPA-estimated fuel economy when the 1500 is equipped with 4WD is 19 mpg combined (16 mpg city/23 mpg highway). In Edmunds testing, a 2WD Ram 1500 crew cab with the V6 and eight-speed automatic accelerated from zero to 60 in 8 seconds flat.

Standard on the higher trims (and optional on all other Rams) is a 5.7-liter V8 with 395 hp and 410 lb-ft. The V8 is matched to one of two automatic transmissions, a six- or an eight-speed. The six-speed is used only on the Tradesman. EPA-estimated fuel economy when equipped with 2WD and the six-speed transmission is 16 mpg combined (14 mpg city/20 mpg highway) and 15 mpg combined (13 mpg city/19 mpg highway) with 4WD. With the eight-speed automatic, EPA-estimated fuel economy improves to 17 mpg combined (15 mpg city/22 mpg highway) with 2WD and 17 mpg combined (15 mpg city/21 mpg highway) with 4WD.

New to the Ram 1500 lineup this year is the optional 3.0-liter turbocharged diesel V6. The diesel is rated at 240 hp and 420 lb-ft of torque and comes with the eight-speed automatic transmission. The EPA estimates fuel economy at 23 mpg combined (20 mpg city/28 mpg highway) with 2WD and 22 mpg combined (19 mpg city/27 mpg highway) with 4WD. In Edmunds testing, a 4WD Ram 1500 crew cab with this diesel engine accelerated from zero to 60 in 9.2 seconds, which is slower than Rams with the gas V6 or V8.

Depending on the cab/bed configuration and axle ratio you choose, a properly equipped Ram 1500 V6 can tow up to 7,450 pounds, while the diesel Ram 1500 maxes out at 9,200 pounds. One with the 5.7-liter V8 can tow up to 10,450 pounds -- which is less than its competitors, but not by much.

Standard safety equipment on the 2014 Ram 1500 includes four-wheel antilock disc brakes, stability control, hill start assist, trailer sway control, front seat side airbags and full-length side curtain airbags. A fully integrated trailer brake controller is optional.

A rearview camera and front/rear parking sensors are either standard or optional on all Ram 1500s. Models with Uconnect Access have an emergency telematics system that connects you with 911 operators at the touch of a button and provides stolen vehicle tracking.

During Edmunds testing, a two-wheel-drive quad cab V6 came to a stop from 60 mph in 128 feet, which is average for a similarly configured full-size pickup. A slightly heavier 2WD crew cab stopped from 60 mph in 133 feet. A much heavier 4WD crew cab with the new turbodiesel V6 engine covered this distance in 135 feet -- a reasonable performance given the diesel Ram's extra weight.

Whether jockeying in city traffic or merging onto a fast-running freeway, the 2014 Ram 1500 moves swiftly and smoothly with any of the three available engines. Gearchanges from the eight-speed automatic are imperceptible, so the transmission never feels busy, as you might expect with so many gears. It's also a benefit when towing, as there are more ratios available to achieve an ideal engine rpm, and it could even limit your need to get a different axle ratio.

While the 5.7-liter V8 has the highest rated towing capacity, the diesel V6 is a close second and it offers more than enough power for towing moderate loads (and better fuel economy to boot). Although the diesel's acceleration numbers are on the slow side, we've found that it's just as capable as the other engines for normal commuting. That said, if you're not planning to do any towing, sticking with the base gasoline V6 engine will save you a bundle. Not only does the gas V6 provide solid acceleration, its power delivery is especially smooth and quiet.

From the driver seat, the Ram feels more refined than its competitors, as its ride quality is smoother and steering more precise than you'd expect in a full-size truck. Running at speed on the freeway, the Ram 1500 is impressively quiet and composed thanks to its coil-spring rear suspension, making it well suited for long-distance drives.

It gets better when fitted with the available air suspension, a unique feature for this class. Not only does it deliver an even more supple ride, but a switch on the dash allows the truck to drop 2 inches to ease liftover and step-in heights when parked. Two off-road settings also allow increases of 1.2 and 2 inches above the standard height for extra clearance. The suspension automatically drops 0.6 inch at freeway speed to improve aerodynamics and save a bit of fuel.

The Ram 1500's cabin is as good as it gets in the pickup segment. Even the lower trim levels boast an attractive design, with quality materials and intuitive controls that are reasonably easy to reach, while the luxurious Laramie's wood-grain trim and leather upholstery is predictably posh. Seasoned truck owners might be thrown off at first by the rotary shift knob on the dashboard (which replaces a conventional shift lever), but it frees up useful space in the front seat, especially in Rams with a center console. The front seats themselves are soft, yet strike an adequate balance between support and comfort. The crew cab's rear seat is very comfortable, offering loads of legroom and an agreeable seatback angle.

Two touchscreen interfaces are available (one 5 inches, the other 8.4 inches) that do a great job of controlling simple and complicated tasks. The touch buttons are large and easy to see at a glance, while physical knobs and buttons provide much appreciated redundant control. Updates to the touchscreen system have made it even easier to use and more visually pleasing than previous models. Other modern convenience features include keyless entry/ignition, adjustable pedals, Bluetooth, voice recognition, smartphone app connectivity and even WiFi hotspot capability.

The Ram provides plenty of standard and optional storage spaces. The quad cab has a clever fold-out flat floor space when you flip up the 60/40 rear seats, while the crew cab features watertight storage compartments under the rear floor as well as shallow bins under the flip-up backseat. Unique to the Ram 1500 is the optional RamBox feature, which places a pair of lockable compartments over the rear fenders inside the truck bed. With the right equipment levels, these compartments can even be locked and unlocked via remote.