OEM also updates SilverStar premium over-the-road tractor As the next step in the expansion of its product offerings, Sterling Truck Corp. has introduced a new family of Class 5 through 8 medium-duty trucks. Named Acterra, the trucks and light tractors combine a 106-in.-BBC cab based on Sterling's heavy-duty L-Line model and a chassis from Freightliner Truck's Business Class.

With production beginning next April, the Acterra is offered in four models: the 5500 (19,500 lb. GVW), the 6500 (26,000 lb. GVW), the 7500 (33,000 lb. GVW), and the 8500 (64,000 lb. GVW). The 5500 and 6500 are single-axle straight trucks, the 7500 is offered as a single-axle truck or tractor, and the 8500 is available as a single- or tandem-axle straight truck or tractor.

The standard engine for all Acterra models is the Mercedes-Benz MBE900 diesel, offered in 4-cyl. 4.3L and 6-cyl. 6.4L versions producing 150 to 280 hp. Power options include the Caterpillar 3126B with ratings from 175 to 300 hp., the Cummins ISB with ratings from 175 to 275 hp., and the Cummins ISC with ratings from 250 to 350 hp. Other powertrain choices include 5-, 6-, 7-, 9-, and 10-speed Eaton Fuller mechanical transmissions and Allison automatics.

Flexibility and custom-engineering will be the distinguishing feature of the new medium-duty line, according to Sterling. The company points out that the vocational market is actually a collection of various segments and niches, each with its own specific medium-truck requirements, and that its goal with Acterra is to satisfy all of those segments by offering a full range of configurations, drivetrains, and options.

Sterling has also introduced new interior and exterior designs for the SilverStar premium over-the-road tractor. The changes include more standard and optional chrome details on the outside and wood-grain accents inside the cab.

Fleets using Texaco Extended Life Coolant (TELC) in Cummins engines should add concentrated silicates to the coolant to avoid problems with silicone gaskets, according to a joint memo issued by Cummins Engine Co. and Equilon Lubricants, the manufacturer of the Texaco product.

The memo supercedes an earlier suggestion by Cummins that TELC be drained from all engines and replaced with conventional coolant to avoid gasket degradation. Truck makers are being asked to suspend factory-fills of the extended life coolant for Cummins engines until a long-term solution to the problem is developed.

Equilon is offering fleets free concentrated silicate additive packages along with installation instructions. The additives will be distributed directly to the affected fleets using OEM sales records.

While silicone seals are widely used in cooling systems, other diesel engine makers, including Caterpillar, Detroit Diesel, Mack, and Navistar, have issued statements supporting the continued use of TELC and other organic acid technology coolants in their engines. Texaco and Equilon recommend that silicate additives not be used with engines from other OEMs that have been factory-filled with TELC.

MGM Brakes of Charlotte, N.C., has released two new series of double-diaphragm and piston-type spring brake actuators. The double-diaphragm design of the LTL-L3 Long Stroke series provides an increased reserve stroke to improve brake efficiency and reduce out-of-adjustment conditions. The brake's non-coil power spring provides an additional 100 lb. of parking force compared to standard 30/30 brakes.

The Magnum Performance Plus series of piston-type spring brakes are smaller and lighter than similarly sized actuators, yet provide increased reserve stroke and better performance with a 3-in. "long-stroke" design. Features include a tamper-resistant design, new sealing and breathing systems to keep out airborne and liquid contaminants, and new protective anti-corrosion coatings for both the power spring and head. Magnum Performance Plus brakes are compatible with S-cam, wedge, and air-disc brakes.

When Freightliner Trucks reached a fork in the road, the company decided to take both paths, Century Class model is the Century Class S/T, which defines one line. The new truck combines all the elements of the current Century Class with additional groundbreaking features.

The S/T (for safety and technology dividing the Century Class family into two distinct product lines.

Replacing the current) incorporates as standard a variety of features either not currently available or offered only as options on the existing product, including:

* Driver's side airbag;

* Collapsible steering shaft;

* Eaton Fuller AutoShift 10-speed transmission;

* Eaton Fuller Solo XL self-adjusting clutch and compression brake;

* LED marker lights;

* Standard daytime running lights;

* Large sloped windshield and large mirrors for improved visibility;

* Eaton Vorad collision warning system.

Other features include an advanced electronic braking system (EBS) and a standard driver message center

Based on the Cat 3406E engine platform, the high-horsepower 14.6-liter C-15 and 15.8-liter C-16 are lighter, more fuel-efficient, easier to maintain, and smarter, according to the Caterpillar Truck Engine Div. of Caterpillar Inc. The two in-line, 6-cyl. engines feature Cat's new ADEM 2000 electronic control system, which is capable of improving engine performance, fuel efficiency, and reliability while still meeting new federal emissions standards, the company says.

The C-15 covers 335- to 550-hp. ratings with peak torques up to 1,850 lb.- ft.; the C-16 is available in a 600-hp. rating (2,050 lb.-ft. peak torque) and a 575-hp. rating (1,850 lb.-ft.). Features include a leak-free seal design, a new Caterpillar electronic unit injector design, geartrain changes that reduce engine noise, and a combination Jacobs compression brake and Cat BrakeSaver hydraulic retarder that can produce up to 720 hp. in braking force. The new high-horsepower engines will be available next month.

Caterpillar has also announced that its 3126B midrange heavy-duty diesel has been upgraded with the ADEM 2000 electronic control package. The new controls allow customers to program shift points with Allison AT/MT and HT automatic transmissions, as well as offer multi-speed PTO options. The 7.2-liter engine also gets a wastegate turbocharger for 250- through 330-hp. ratings for better bottom-end response, improved fuel economy, and decreased heat rejection, according to the manufacturer.

Bering Truck Corp. unveiled its new LD Series Class 3-4 trucks at the Great American Trucking Show last month. In addition to driver comfort features such as an extended cab and suspension seat, the new family offers as standard the DDC 638 turbodiesel Allison AT-542 automatic transmissions, Hayes Lemmerz steel wheels, Racor fuel filters, and Kysor cooling fans.

Bering also took the wraps off its HDMX Class 8 Mixer, the first in the MX Series to offer a tight turning radius. A Sauer-Sundstrand Transit Mixer System eliminates mechanical cables and produces a near-constant low drum speed during transit, helping to improve fuel economy and reduce drum wear. In addition to the extended cab and ergonomic air-suspension seat, standard features include the Cat C-12 engine, Eaton 11-speed manual transmission and Solo self-adjusting clutch, Kysor fuel tanks, Delco Remy starters and alternators, and Hayes Lemmerz steel wheels.

Based on the Cat 3406E engine platform, the high-horsepower 14.6-liter C-15 and 15.8-liter C-16 are lighter, more fuel-efficient, easier to maintain, and smarter, according to the Caterpillar Truck Engine Div. of Caterpillar Inc. The two in-line, 6-cyl. engines feature Cat's new ADEM 2000 electronic control system, which is capable of improving engine performance, fuel efficiency, and reliability while still meeting new Federal emissions standards, the company says.

The C-15 covers 335- to 550-hp. ratings with peak torques up to 1,850 lb.- ft.; the C-16 is available in a 600-hp. rating (2,050 lb.-ft. peak torque) and a 575-hp. rating (1,850 lb.-ft.). Notable features include a leak-free seal design, a new Caterpillar electronic unit injector design, geartrain changes that reduce engine noise, and a combination Jacobs compression brake and Cat BrakeSaver hydraulic retarder that can produce up to 720 hp. in braking force.

The new high-horsepower engines will be available next month.

Caterpillar has also announced that its 3126B midrange heavy-duty diesel has been upgraded with the ADEM 2000 electronic control package. The new controls allow customers to program shift points with Allison AT/MT and HT automatic transmissions, as well as offer multi-speed PTO options. The 7.2-liter engine also gets a wastegate turbocharger for 250- through 330-hp. ratings for better bottom-end response, improved fuel economy, and decreased heat rejection, according to the manufacturer.

Specifically developed to complement extended oil drains, Mobil Delvac Xtreme Service Grease can handle lube intervals of up to 30,000 mi. The new high-viscosity grease formulation combines an anti-wear package with a high-tack polymer for improved water-wash resistance. It is suitable for all truck and heavy-equipment chassis grease points.

The company has also announced that its Mobil Delvac 1 and Mobil Delvac 1300 Super engine oils have been upgraded to handle diesel engines certified for the stricter 1999 emissions requirements. The new formulation for the fully synthetic Delvac 1 includes changes to detergent, dispersency, and anti-wear performance, as well as antioxidant additives to handle higher carbon soot levels. The reformulated Delvac 1300 Super uses advanced Mobil base oil technology.

A new 40,000-lb.-capacity tandem drive axle from Dana Corp.'s Spicer Heavy Axle and Brake Div. is designed to handle high-horsepower, high-torque engines without special electronic engine controls. The company has also introduced a new family of single drive axles with capacities ranging from 21,000 to 26,000 lb. Both new axle models will be available as part of the Roadranger System of drivetrain products, a joint marketing arrangement between Dana and Eaton Corp.

The High Performance-40 - Model DSH40-(P) - weighs approximately 400 lb. less than other high-torque tandems, but is approved for use with engines producing up to 650 hp. and 2,050 lb.-ft. peak torque. Features include a stronger axle housing, 15.75-in. hypoid gearing, high-capacity Timken bearings, and a new power divider with improved internal lubrication flow. Axle ratios range from 3.08 to 4.88.

Options for the high-torque drive axle include the Dana Spicer LMS hub system and a factory-filled synthetic lube for an initial 500,000-mi. drain interval.

The single drive axle family draws on many of the same design improvements developed for the new tandem, including hypoid gearing and premium Timken bearings. The axles, which will replace the current Dana Spicer 21080, 23080, 26080, and W230 models, are rated up to 90,000 lb. GVW and offer 2.85 to 7.17 ratio coverage.

Cummins Engine says it now has full production availability of its ISX 15-liter diesel, including two new 475-hp. ratings. The ISX, offered in ratings ranging from 400 to 600 hp., is positioned to take over as Cummins' big-bore fleet diesel. Production of the N14 Plus will be phased out over the next three years.

The engine is designed to meet tightening emissions requirements and driver preferences for more usable power. Mechanical features include an integrated engine brake that delivers up to 600 hp. of braking force, separate overhead camshafts for valve and injection actuation, and electronic controls with more processor power.

The 475 and 500 hp. will be offered in a 1,650 lb.-ft. version and a SmartTorque 2 version that adds 200 lb.-ft. of torque when the transmission is in the top two gears. The ISX 400 and 450 are for the "fuel economy sensitive fleet" and have peak torque ranging from 1,450 to 1,650 lb.-ft. SmartTorque versions are also offered.