Driving Peterbilt's 365
It's a lot like a 357, but without the diesel exhaust odor.
By Tom Berg
Senior Equipment Editor
What's in a model number? For Peterbilt Motors and its numerical designations, it's pretty much about the EPA 2007 diesels, which cost many millions of dollars to engineer in and certify. Although Pete upgraded interiors and added new equipment to some models, the engine switchover mandated for January is the big kicker that prompted managers to give new number-names to most of their highway and vocational tractors and trucks.
One is this Model 365, which will replace the 357 that's long been a popular dump and mixer chassis in many markets. Like the 357, the 365 can be ordered with either a set-forward or set-back steer axle to maximize loading in bridge-formula or axle-weight states. It has a medium-length nose to house 9- to 13-liter engines from Cummins and Caterpillar. A companion truck in Peterbilt's new vocational lineup is the 367, with a long nose to take 15-liter engines.
The 365 looks and drives like a 357 because, except for the engine changes, it's pretty much the same truck. It's got the same 370-series aluminum cab, steeply sloped hood, brutish nose, flat fenders and headlight pods mounted to the hood. The polished aluminum "crown" around the grille is now a single piece that shines even nicer in the sunlight than the previous multi-piece design.
Each pod holds one halogen sealed beam lamp that's said to be more powerful than those in the 357, and of course a turn signal/parking light is part of the pod. Being on the hood, a pod is less likely to get whacked if a fender does, and that could save some dough. There was more than enough sunlight the day of my drive, so I didn't get to test the headlamps.
There was also more than ample heat on this late-August day, with the temperature readout on the instrument panel reading "104 F" as I was leaving the premises of Peterbilt's plant in Denton, Texas. I just cranked up the air conditioning and did just fine.
Outside it was so hot and humid that I left the engine running and the A/C on as I walked around shooting pictures. This violated my own anti-idling rule (why foul the air?) and I'm sorry, but I wanted the cab cool for when I jumped back in. I could also claim to be testing the new "high efficiency" cooling system needed for the '07 diesels, which throw off more heat than current engines.
The cooling system's principal part is a 1,438-square-inch radiator core, which is about 30 percent bigger than that in the old radiator. I made it a point to check the temperature gauge to see if it stayed in the normal range, and it did, hardly wavering from about 210 degrees – fine for a pressurized system on such a hot day.
While scurrying about with the camera, I realized that I wasn't smelling any exhaust odor. I mean, there was absolutely no diesel aroma, or stink, depending on your point of view, or smell. The new '07 emissions controls had so seriously pinched down oxides of nitrogen – the source of the characteristic smell of diesel exhaust – that the smell is gone, and that should make a lot of people happy. There was absolutely no smoke coming out the stack, either.
The credit for this goes to the people who developed the combustion advancements in the '07-spec Caterpillar and Cummins diesels offered with this truck, and of course the diesel particulate filters that they'll be fitted with. The combination DPF and oxygen catalyst for this truck's Cummins ISM-350 was on the stack, where it looks like a big muffler with wires running to it.
Those wires connect sensors in the aftertreatment "can" to engine controls that trigger an active "regeneration" when the filter loads up with soot and must be burned out. It was way too soon in this diesel's life for this to happen, and when it does it'll get to 1,000 degrees or more inside. But it's not likely that the driver or nearby workers will ever notice the heat. The device is double-walled, the stack is well shielded and the tail pipe is high above the ground.
The 365's big, wide hood took a good yank to tilt forward, and it locks in place so wind can't blow it back down until a sliding lever is released. On most trucks, the lock is on the curb side, where I unsuccessfully looked for it until Derek Smith, Peterbilt's public relations manager, pointed out that the lock's on the left side of this truck. Good thing he was there, or the truck would still be sitting with its hood open.
The 350-horse Cummins sounded nice and behaved well. It didn't have a lot of guts, but it was brand new and far from broken in: The odometer showed only 29 miles when I left the Denton plant. The mixer drum was empty, so I skip-shifted through the 11-speed Fuller "LL" and never used its low-low ratios. The tranny shifted smoothly if I remembered to move the stick quickly, which you must do with most modern engines.
The drum was empty because this is one of Peterbilt's 2006 show trucks, Smith explained. Managers didn't want to risk scratching the funnel with crushed rock or some other ballast material, as they had last year with a 357 mixer that I drove. Whoever eventually buys this new 365 will probably get to load the drum for the first time, and will enjoy the dazzle of its Viper Red cab and nose that contrasts nicely with the Kimble mixer body's bright-white paint.
From the plant, I headed to Interstate 35 and swung north, going as far as Sanger, a small town that seems to lack "destination" qualities but does have enough streets with bruised concrete and asphalt to give a good workout to suspensions over the axles, under the cab and beneath the seat. The ride was pretty good, considering the axle suspensions' high ratings (20,000 and 46,000 pounds) and that empty drum.
Big "duplex" tires on the steer axle limited wheel cut and made for a wide turning circle, but it wasn't bad if I cranked the wheel early in a turn, especially while backing up. TRW dual-power assist removes the work in hard turns, but also introduces some vagueness at highway speeds – normal for an extra-heavy-duty front axle.
While driving and during pauses to shoot photos, I got reacquainted with Peterbilt's stout cab. It sits high off the pavement on the 365 chassis, as it does on a 357, and is narrow by some comparisons, but is plenty roomy for construction duty. There's enough space for two seats, including a low-back passenger seat that squeaked annoyingly while under way. Between them is a big console with switches and other controls for the mixer. There were two holes where the pusher-axle switches will go, and the rear booster axle was disabled. So I couldn't drop the auxiliary axles if I wanted to, and the truck was a 10-wheeler for this trip.
Interiors were redesigned last year for the 357 and are carried through to the 365. This truck had the base Pro-Bilt interior, which looked nice and is practical, though its vinyl seat covers are sticky.
From the high-backed driver's seat there's a good view through the windshield and over the sloping hood. Although its bulky width would seem to hide what's alongside to the right, I never actually missed seeing anything during my trip, and if I did it didn't honk or holler. The view in other directions is excellent. There's a big window on the rear wall, neat curved corner windows and a peep window in the passenger door. This truck has motorized Moto Mirrors, but they were set just-so and I never needed to remotely adjust them.
On the tall, wide instrument panel were two rockers for the cruise control, which I used while zipping along I-35. I usually cruised at 60 mph, which in top gear was a little over 1,700 rpm on the tachometer. That to me would be fast enough with nine or 10 yards of concrete aboard and all axles down, but the truck's overall gearing would let a guy in a hurry make even better headway.
So, this is how Peterbilt's mixer customers will zip into the future, in a truck that has a lot of familiar features along with the necessary advances to meet the new emissions standards. Does it add up to enough to justify the new model number? If I had been among the Peterbilt people who worked so hard to get this truck to market, I'd say yes.
If I were a buyer who will be asked to spend thousands of extra dollars over a predecessor model to acquire one – maybe a thousand bucks per nomenclature point – I might feel my investment more than paid for a higher model number. If I were the driver of this 365, I think I'd enjoy going to work and, with the cleaner-burning engine, I'd definitely appreciate breathing easier. n
