Fuel econemy question
in [Technical]
|
Prev: Suggestions from your experience organizing metric & englishc...
Next: anyone have an old Trico catalog?
From: Don Stauffer on 9 Jul 2010 10:23 hls wrote: > > "Jesse" <sumin(a)telus.net> wrote in message >>> >> Thanks everyone, I'll give this up. I hoped that there was some >> correlation of mpg to rpm. > > No, there isnt. For your daughter, you want something very dependable, > with reasonably good mileage, that handles well and can keep her relatively > safe. > I suggest you forget the mpg to rpm ratios. I would disagree. The way to improved milage is to maximize throttle opening while minimizing rpm. Keep in highest gear possible. The throttle opening thing also requires one to stay below the power enrichment point. This comes at somewhere around 3/4 throttle. Below power enrichening, higher throttle settings burn fuel more efficiently because the effect compression ratio is higher (partial throttle lowers compression ratio).
From: E. Meyer on 9 Jul 2010 12:23 On 7/9/10 9:23 AM, in article 4c3730c9$0$48226$815e3792(a)news.qwest.net, "Don Stauffer" <stauffer(a)usfamily.net> wrote: > hls wrote: >> >> "Jesse" <sumin(a)telus.net> wrote in message >>>> >>> Thanks everyone, I'll give this up. I hoped that there was some >>> correlation of mpg to rpm. >> >> No, there isnt. For your daughter, you want something very dependable, >> with reasonably good mileage, that handles well and can keep her relatively >> safe. >> I suggest you forget the mpg to rpm ratios. > > I would disagree. The way to improved milage is to maximize throttle > opening while minimizing rpm. Keep in highest gear possible. > > The throttle opening thing also requires one to stay below the power > enrichment point. This comes at somewhere around 3/4 throttle. Below > power enrichening, higher throttle settings burn fuel more efficiently > because the effect compression ratio is higher (partial throttle lowers > compression ratio). .... But the guy is trying to pick one car over another. How does this help? Is there a table of optimized throttle/rpm somewhere?
From: hls on 9 Jul 2010 14:06 "Don Stauffer" <stauffer(a)usfamily.net> wrote in message news:4c3730c9$0$48226$815e3792(a)news.qwest.net... > hls wrote: >> >> "Jesse" <sumin(a)telus.net> wrote in message >>>> >>> Thanks everyone, I'll give this up. I hoped that there was some >>> correlation of mpg to rpm. >> >> No, there isnt. For your daughter, you want something very dependable, >> with reasonably good mileage, that handles well and can keep her >> relatively >> safe. I suggest you forget the mpg to rpm ratios. > > I would disagree. The way to improved milage is to maximize throttle > opening while minimizing rpm. Keep in highest gear possible. You have to be reasonable in your expectations of how another person will drive. We all know that the driving profile has a lot to do with mileage. And for most of us, modifying the driving profile is like being on a diet or exercising...we may do it for a while, but if it is not part of our daily life, it probably wont become part of our daily life. Check out a few cars, and -with respect to mileage- you get what you get. You still cant make a silk purse out of a sow's ear.
From: Scott Dorsey on 9 Jul 2010 14:41 hls <hls(a)nospam.nix> wrote: > >You have to be reasonable in your expectations of how another person >will drive. We all know that the driving profile has a lot to do with >mileage. A neighbor of mine, quite a few years ago, came to me because his car had suddenly started getting really terrible mileage. I went over it and changed points and plugs and cleaned the carb and everything seemed perfectly fine to me. He kept it for a few weeks, and reported the mileage hasn't improved at all. When I asked if anything had changed with his driving habits, he remarked that his teenager had started driving the car. Problem solved. Well, not really solved, but at least identified. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis."
From: ben91932 on 9 Jul 2010 15:06
(partial throttle lowers > compression ratio). Unless the engine has agressive egr programming... |