"New" to fuel efficiency

Discussion in 'Start Your Journey Here' started by mcbass, Jun 23, 2008.

  1. mcbass

    mcbass New Member

    Hi everyone. I'm new to the forums, but not new to trying to save fuel.

    I kind of discoverd "hypermiling" on my own as a way to pass the time during my 78 one-way miles commute into Northern Maine. At the time, I owned a 1997 Nissan Sentra. The car didn't have power brakes or steering, so I would very routinely shut the engine off and coast. It got to the point that I could coast nearly 15 percent of my actual commute. I was averaging about 45mpg. (Car had no cruise control)

    I now own a 2003 Accord w/ 4 cylinder (EX?). The car has both power brakes and steering, so I don't generally every turn off the motor to coast, but still coast just as much. When I'm not coasting, I have Cruise Control on most of the time. I heard about, and am going to buy an SGII asap. I get up to 42 mpg with this vehicle.

    I'd like to know a couple of things:

    1. Is it harmful to my engine running low rpms in high hear? EX. I can go 30 mph in 5th on cruise control. My friend is a technician and he told me it wasn't good for it, but I've read otherwise...I'm looking for more opinions, especially from those that may have direct experience.

    2. Are there any devices with could aid in my coasting? I think I've read an article that mentioned that so-and-so had a car rigged to turn the motor off whenever the brake pedal was pressed and come back on again when needed? Huh?

    3. My technician friend told me that over-inflating my tires will actually cause them to wear appreciably sooner than the recommended level of inflation and that replacing tires sooner would negate any savings from the over-inflation. How about some input on this one?

    4. Here's the standard "idle vs shut off" question. I've taken to turning the Accord off if instead of idling. Years ago, it was taken from granted that restarting the vehicle would use more fuel than you would have if you'd just idled. I've read that fuel injection makes this untrue. Is it? Is there a guideline?


    I guess that's all for now!

    Thanks!

    mc
     
  2. nissynis

    nissynis NC Attorney

    Welcome! Sounds like you already know what you are doing.

    Here's a few thoughts:

    3) There is evidence that hyperinflating your tires is good for wear, because it reduces the chance of wearing out the edges. Some say that you'll have increased center wear at higher psi, but it appears that the psi needed for that to occur is remarkably high, and well above the sidewall max (a popular choice around here: http://www.cleanmpg.com/forums/showthread.php?t=10881)

    4) Fuel injection does indeed yield a new rule of thumb: keying the ignition uses about the same gas as 10 seconds worth of idling. So, if you are going to get a coast or a stop of 10 seconds or more, considering using FAS.

    Good luck!
     
  3. Skwyre7

    Skwyre7 Well-Known Member

    Welcome! It sounds like you've got a good start. I'll see if I can shed a little light on your questions.

    No. You'll probably do better without the CC though.

    None that I know of. If your car is a MT, then FAS is possible, if you're comfortable with that.

    Your friend is incorrect. Tires at the max sidewall pressure will last longer than tires that are at the manufacturer's recommendation (which is set for comfort, not tire life). Upping your pressure will also help with your glides. Upping your pressure to the max sidewall is also completely safe. You won't get a blowout, etc. (That's more common in under-inflated tires.)

    Modern engines, when warm will (on average) use less fuel during start up than idling for about 10 seconds.

    If there's more, feel free to ask.
     

Share This Page