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Posted: August 1, 2014 by Jim Park

Peterbilt’s new 386 will please drivers and fleet managers, both.

A very tidy compromise. That’s what I’d call the latest addition to the Peterbilt lineup. Introduced at Mid-America earlier this year, the Model 386 fills the gap between the long-nose 379 and the less traditional, but fully aerodynamic 387. Drivers and owner-ops looking for the classic long-hood styling of the 379, but with an aerodynamic edge, will find the 386 suits them to a ‘T’.

We’ve heard it’ll be very competitively priced with a long list of options, including cab-mounted exhaust, a full range of sleepers (36-, 48-, 63-, and 73-in.; double or single bunk), and two fully customizable interior packages. Powertrain options will run the gamut from traditional fleet spec to full owner-op spec, with Cat C13 and C15 engines, and Cummins ISX engines.

The 386 uses the same cab as the 379, but with a few enhancements to the basic design. The passenger door window-sill sits a couple of inches lower than before, and the passenger door porthole window is larger than ever for improved visibility. The cab itself sits 2.5 in. higher on the frame than a 379, adding that much more altitude to the view from the cab.

The sleeper on the truck I had included an upper bunk, which limited storage space to a minor extent, but it still had room for a fridge and microwave, as well as an entertainment center and plenty of room for the necessities. Right- and left-side sliding, tinted glass windows provided a decent cross-breeze when I slept with the engine off.

This truck is everything a driver would expect from Peterbilt. All the class and comfort is there, wrapped in a stylish, fuel-efficient package that comes with an attractive bonus: lower fuel costs.

The Truck

The 386 is ’07 ready, Peterbilt says. Engineers have optimized the cooling package in preparation for the hotter-running ’07 engines by sitting the rad in front of the front cross member rather than on top of the frame rails. The underside of the hood is smooth for improved airflow around the engine. While I can’t promise that they’ve worked out all the challenges, I can say the fan on this one ran a lot less frequently than I would have expected for the conditions. That’s a good sign.

Bobtail, the steer axle tipped the scale at 11,520 lb (with me in it). The drives were at 8580 lb. The steer axle is set back 50 in. from the bumper, keeping a lot of the cab, engine, and sleeper weight up front. I ran loaded at 78,960 lb, and with the 5th-wheel set an inch ahead of center, I scaled the drives at 33,460 lb. The steer axle went to 11,800 lb. Drivers will like the fact they can run the 5th-wheel close to center for a better ride without putting the drive axle over the limit.

The Powertrain

This truck was built for the PACLEASE rental fleet, and so had a typical fleet drive train. The 475 Cat C15 did a good job with the 79,000 lb GVW, but its full potential might have been limited by the 9-speed transmission.

Top gear is a direct 1:1 ratio with substantial steps between the gears. The truck was obviously geared to run at 60 mph, where the C15 could have run at 1325 rpm, just the way Cat says it should be run. I ran the truck at Texas speeds – between 60 and 70 – and my fuel economy took a dive. In fact, an American colleague, Steve Sturgess of roadSTAR magazine, took the same truck on a shorter ride – after Peterbilt put a roof fairing on the truck – and beat my fuel mileage by 2.2 mpg. I made 4.6 mpg on my 1000-mile trip; Sturgess hit 6.8 on his 300-mile trip.

Sturgess said he kept to 60 mph, running the engine at 1325 rpm. I ran between 65 and 70, turning the Cat up to 1425-1550 rpm. I pulled about 200 two-lane miles as well, which often forced me down into 8th gear. The spread between the gears was too great to keep the engine happy at 50 mph in top gear.

Readers shouldn’t take this as a negative comment on Cat’s fuel economy, but rather as a lesson on the need to spec for the operating conditions, and to run to the spec. Going only 200 rpm beyond the optimum speed of the engine cost me 2.2 miles per gallon.

The fairing would have helped, and perhaps his driving technique, but I believe my driving skills (speed notwithstanding) would pass muster with Cat: shift low – below 1000 rpm, easy on the pedal, low rpm in a climb, no idling, etc. I definitely wasn’t pounding on it.

On the Road

Peterbilt kindly let me have the truck for a couple of days, and I made the best of the time, spending two nights in the sleeper, and logging 998 miles. I ran in a big circle from the plant in Denton, TX, west to Odessa, south to Fort Stockton, east to Austin, and north back to Denton. In all, I covered about 200 miles of two-lane as well as the Interstate miles to see how it ran in less than ideal conditions.

Drivers will appreciate the smooth, quiet ride of this truck. It held the road well, and the 50°-wheel-cut made it a snap to wheel around tight corners. The Sheppard M100 power steering was a bit stiff for palming the wheel in a tight spot, but the feel on the highway was terrific.

The irritants were few, and minor ones to boot. For example, while there’s adequate storage space in the cab, there’s not a lot of room on top of the dash. The doors to the under-bunk jockey boxes were keyed the same as the door and the ignition, and remained locked. You’d need an extra key to get them open, or be constantly taking the key from the ignition. And last, but not least for some, the ashtray is impossible to see in the dark. A dim light down there would help a lot.

Lasting Impressions

Drivers will like the traditional Peterbilt cab, and get an extra buzz from the terrific maneuverability and visibility of the 386. Drivers in team operations will certainly appreciate the smooth ride and quiet cab. The truck appears easy to maintain, with terrific access to all the daily inspection points. The hood tilts better than 90° over and the lack of external hardware with the front disc brakes leaves lots of room between the inside of the front wheel and the frame. And here’s a plus: the new front bumper – made of an advanced composite material called Metton – is said to be nearly bulletproof.

Canadians will be happy to learn that the 386’s 49.8-in. front-axle setback keeps it comfortably under the 244-in. wheelbase limit, even with the longest sleeper Peterbilt has on the books – the 70-in. UltraCab.

As a company driver, I’d be pleased to learn that I had been assigned one of these, and as an owner-op, I’d see the advantage of running a traditional Peterbilt cab and chassis with improved aerodynamics and good weight distribution – not to mention an attractive price and an impressive list of customizing options.

Spec Sheet: Peterbilt Model 386

Engine: Cat ACERT C15 475-hp @2100 rpm, 1650 lb ft @ 1200 rpm

Transmission: Eaton Fuller RTOC 16909A 9/13-speed convertible

Clutch: Eaton Fuller 15.5-in. Easy Pedal VCT Plus

Front axle: Dana Spicer E1202 W 12,000 lb, Peterbilt 12,000-lb taper-leaf springs, Bridgestone R280 295/75R22.5 tires

Rear Axle: Dana Spicer DSP 40, 40,000 lb, 3.55:1 ratio, Peterbilt low air leaf suspension, 40,000 lb, Bridgestone M726 EL 295/75R22.5 tires

Brakes: Bendix air-disc brakes up front, Dana Spicer ES brakes at the rear with
Haldex autoslacks, MGM TR 3030 chambers

Wheelbase: 240 in.

Tare weight: 20,100 lb (steer, 11,520 lb; drives, 8580 lb, full fuel)


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