View Single Post
Old 04-20-2010, 12:09 AM   #12 (permalink)
Ryland
Master EcoModder
 
Ryland's Avatar
 
Join Date: Jan 2008
Location: Western Wisconsin
Posts: 3,903

honda cb125 - '74 Honda CB 125 S1
90 day: 79.71 mpg (US)

green wedge - '81 Commuter Vehicles Inc. Commuti-Car

Blue VX - '93 Honda Civic VX
Thanks: 867
Thanked 434 Times in 354 Posts
Quote:
Originally Posted by blownb310 View Post
That's the first time I've heard that. Are you saying that diesels don't return good economy in short trips? Even in the summer?
Correct, when they are cold you advance the timing and that is hard on the engine, also because the engine is cold it's not burning all the fuel because it's relying on heat to ignite that fuel, leading to poor fuel mileage.
You also have glow plugs that are pretty much good for a set number of starts before they burn out and have to be replaced, the starter is also rather large leading to a large battery that needs to be fully charged or it will shorten it's life as well, this happens best by letting it run.
They also have 22:1 compression or higher, leading to fuel in the oil unless it's cooked out by warming the engine up fully, because of that high compression you tend to have a heavy engine block that takes longer to heat up.
  Reply With Quote