• The E7 engine is used primarily in commercial trucks.Big Mack Truck image by evillager from Fotolia.com
  
  The E7 engine was first produced by Mack in 1988. It is a heavy-duty, inline, six-cylinder diesel engine that is used primarily in commercial 18-wheeler trucks. The engine underwent some modifications over the years and was in production from the late 1980s into the 2lst century.
  
  

Power Specifications

• The E7 is a four-cycle engine and utilizes direct injection technology. The total piston displacement is 12 liters, or 728 cubic inches. The total power rating of the E7 is between 250 hp and 454 hp, or 186 kW and 298 kW, at 1,700 RPM to 1,800 RPM. When the horsepower is rated at 250, the torque is 975 lb-ft at 1,200 RPM. With horsepower at 300, the torque is 1,160 lb-ft at 1,200 RPM. A horsepower of 350 on the E7 brings a torque of 1,360 lb-ft at 1,200 RPM. Power at 400 hp at 1,800 RPM brings a torque of 1,460 lb-ft at 1,250 RPM. When horsepower measures at 454, torque is 1,660 lb-ft at 1,200 RPM.
  
  

Features

• The original E7 was turbocharged and featured a body-mounted air-to-air after-cooled system. In 1990, Mack developed an electronically controlled and variable injection timing system. This system was called the Econovance Variable Injection Timing system and it optimized fuel efficiency and reduced emissions. This system was only used on the E7 engine. In 1991, Mack added another modification to the E7, the High Swirl/Moderately High Injection Pressure Combustion System, enhancing the mixing process of air and diesel fuel. This improved combustion efficiency and fuel economy while reducing emissions, maintaining proper oil viscosity and expanding oil change intervals.
  
  

Other Information

• The E7 engine series has grown exceedingly popular since its introduction in 1988. Because of its relative popularity and quality performance, over the years Mack increased the E7 line to have 16 different versions. In 1999, Mack introduced the E7-460, which sported the Mack E-Tech technology. According to the official Mack Trucks website, "The E7 boasts the industry's best horsepower-to-weight ratios for customers concerned with achieving maximum productivity." After its introduction in 1989, the E7 was designed to meet the Environmental Protection Agency's emission standards for 1990, and has since undergone modifications to meet increasingly stringent emissions rules.