View Single Post
Old 04-05-2020, 08:31 AM   #13 (permalink)
Frank Lee
Frank Lee's Avatar
Join Date: Jan 2008
Location: up north
Posts: 12,732

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,571
Thanked 3,507 Times in 2,194 Posts
All signs point to that piston speed range as a good proxy for when you don't have a BSFC chart.

Years ago I inquired here about optimal piston speed and why wouldn't slower be better (because the calcs showed my F150 so different from the cars and bikes)? There is a sweet spot between too slow (excessive heat loss through head, piston, cylinder walls) and too fast (higher internal friction).

Last edited by Frank Lee; 04-05-2020 at 08:36 AM..
  Reply With Quote
The Following User Says Thank You to Frank Lee For This Useful Post:
maczo (05-11-2020)