Xfinity cars. Teams have an option of building their own engines or they may run a specification engine, similar to what is used in many short tracks. Both engines are V8, pushrod, 12:1 compression motors. "Built" motors are built to team specifications using any configuration of pieces as long as it still meets NASCAR specifications. The spec engine is built using NASCAR-Approved pieces that may be purchased from an approved supplier. The engines may be purchased as a kit or pre-assembled. All of the spec pieces are individually encrypted with a barcode for verification and tracking purposes and can be checked during the inspection process with an encryption reader. NASCAR has a specification supplier for the series-specification engine. When the series first started, the cars ran a V6 engine with a maximum displacement and no compression limit. In the early/mid 1990s the V8 engine with a 9.5:1 compression and maximum displacement was introduced to the series as an alternative to the V6 engines. Due to the decrease in popularity of the V6, it was phased out for the 1999 season. When the East and West series rules were combined, the compression ratio changed to 12:1. Menards Series cars use Sunoco racing fuel, NASCAR's specification fuel. For races run with national series, the cars run an E15 blend since the national series uses such fuels. The cars use radial tires. Along with the rest of ARCA and NASCAR's international series, the Menards Series have General Tire as their exclusive tire supplier. On November 4, 2014 at the SEMA Show in Las Vegas, NASCAR president Mike Helton unveiled a new body style for the K&N Pro Series based on the NASCAR Cup Series Gen 6 models. The new body, developed with Five Star Race Car Bodies, is constructed of a composite laminate blend and designed with easily replaceable body panels, expected to shrink the costs of fabrication dramatically. The body style is eligible for use in both Menards Series competition and ARCA Racing Series competition, replacing the old Gen 4-style steel bodies after 2015, and the current one-piece composite body after 2016. Specifications Engine displacement: 358 cu in (5.8 L) Pushrod V8. Transmission: 4 speed Manual. Weight: 3,300 lb (1,497 kg) Minimum (without driver). Power output: ~650 hp (485 kW) unrestricted. Fuel: Sunoco Leaded or Unleaded gasoline. Fuel capacity: 22 U.S. gallons (83.2 L). Fuel delivery: Carburetion. Compression ratio: 12:1. Aspiration: Naturally