The VW "Type 4" engine was originally made for the VW 411/412 (1.7 liters). The 912E uses a Porsche-designed revision of the engine (2.0 liters) with a longer 71mm stroke crankshaft, new rod bearings and new pistons to increase the cylinder bore to 94mm. The 912E's Bosch L-Jetronic / Air Flow Controlled system was later adapted for the 911. The cost for a good rebuild of the 911 flat six is $10,000 while the cost of the 912E flat four rebuild is less than half that. The 912E has a 20+ gallon fuel tank, 30 mpg and 600-mile range.