Performance parts for a car typically improve the acceleration at the expense of fuel efficiency. Modifications typically include a longer and higher cam duration, intake and exhaust manifolds tuned for higher engine speeds, a lighter flywheel to reduce inertia at the expense of idling stability, and shorter gearing for a greater mechanical advantage at the expense of higher engine speed. Proposed are engine modifications designed for fuel efficiency at the expense of performance. The camshaft would be tuned for a shorter duration to optimize slower engine speeds (although a high lift would still make sense). The intake and exhaust manifolds would be tuned for lower RPMs. The flywheel would be heavier to enable a slower idle speed. The gearing would be taller to turn the engine more slowly and put it under more torque load at cruising speed.
-- kevinthenerd, Feb 20 2017

Baked and WKTE.
-- 8th of 7, Feb 20 2017



random, halfbakery