Comments by "John Luetjen" (@jehl1963) on "How to Maximize MPG! Simple Ways to Save Money on Gas - '22 Honda Civic Si (POV Binaural Audio)" video.

  1. When I was younger my dad always told me to avoid "jack rabbit starts" and to accelerate gently. Back in the 80's BMW tested that idea (and others) prior to developing the 325e. What they concluded is that long gentle acceleration uses more fuel than accelerating swiftly to cruising speed. This was because of the amount of time that it took to accelerate "gently". The longer that this period was extended, the more fuel that was wasted. My experience is that the most efficient method is to accelerate up to the peak torque engine speed and than shift to the next gear. Above the peak-torque RPM, the engine starts to become air limited (even though the HP continues to increase as initially the torque doesn't drop as fast as the revs are increasing) and the pumping losses increase. Increased pumping losses results in decreased mileage. This concept prompted the development of the engine for the (often derided) BMW 325e, which had a torque curve more akin to a diesel than a high-speed gas engine. While the sportier 325i engine developed 168 HP at 5800 RPM/164 lb-ft of torque at 4300 RPM, the more efficient 325e engine generated 121 hp at only 4250 rpm, and a relatively strong 170 lb-ft of torque at 3250 RPM. The reduced rev range allowed lighter components in the engine, softer valve springs and other changes, all of which reduced friction (which contributed to the higher torque, the result of an increased Brake Mean Effective Pressure (BMEP) at lower rev's).
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  2.  @sesh3508  Yes, I often do that too. For example; accelerate briskly through 4th gear and then jump to 6th to cruise.
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