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Gas Mileage down? - Spring is coming

  #11  
Old 03-06-2006, 04:39 AM
Sledge's Avatar
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Default Re: Gas Mileage down? - Spring is coming

w00t!

Today was my first ever morning commute that my trip MPG ended up higher than when I started. Yay for for starting your car at 27F instead of 10F!
 
  #12  
Old 03-06-2006, 04:16 PM
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Default Re: Gas Mileage down? - Spring is coming

The weathers helping me too, after several 25-26mpg tanks this current tank is way up from there. Scangauge is at 28.5 for the tank so far and my daily average for today was 31.5. Should be getting into the 30 all summer long.
 
  #13  
Old 03-06-2006, 04:41 PM
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Default Re: Gas Mileage down? - Spring is coming

Originally Posted by Sledge
w00t!

Today was my first ever morning commute that my trip MPG ended up higher than when I started. Yay for for starting your car at 27F instead of 10F!
And to think I complain when I'm driving in 30deg instead of 40...
 
  #14  
Old 03-06-2006, 07:20 PM
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Default Re: Gas Mileage down? - Spring is coming

Originally Posted by Sledge
Yay for for starting your car at 27F instead of 10F!
Yeah, I'm *so* looking forward to that - at least we've gone from -10F last week up to 15F this week.

I've been logging my morning commutes, and it looks like about a 2 mpg change for every 10F - anybody else have data like that?
 
  #15  
Old 03-06-2006, 07:28 PM
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Default Re: Gas Mileage down? - Spring is coming

All of you northern tier drivers have my undying sympathy. I just did 494 mile on 7.688 gallons to get 64+ mpg for a tank. Sorry about bragging but I am elated and can't help myself. The temp soared to 85 here in Dallas for a couple of days and I reaped the benefits. I did get 52.5 the tank before ( 40-50 degrees) and am looking at 61.2 mfd this tank (220 miles). So hang tough. Your mpg will improve dramatically once it warms up in a few weeks.
 
  #16  
Old 03-06-2006, 10:12 PM
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Default Re: Gas Mileage down? - Spring is coming

Originally Posted by wundej

The problem with warmer weather is that your intake charge temp will go up, which isn't the best way to make the most efficient power. This is why you generally see a lot of the aftermarket intakes for car labeled "cold air intake" which usually means that they pull air from a cooler spot than the engine bay (usually the fender well or grill).
This is contrary to better fuel economy. Warm weather is better. With warm-air intake, the gasoline more readily vaporizes, and you get more complete combustion, and less waste = higher fuel economy.

Maybe cold air intake is good for street rods and superchargers, and when getting the very last horsepower at terrible MPG matters to you, but its NOT good for Hybrids!!!
 
  #17  
Old 03-06-2006, 10:53 PM
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Default Re: Gas Mileage down? - Spring is coming

Originally Posted by gpsman1
This is contrary to better fuel economy. Warm weather is better. With warm-air intake, the gasoline more readily vaporizes, and you get more complete combustion, and less waste = higher fuel economy.

Maybe cold air intake is good for street rods and superchargers, and when getting the very last horsepower at terrible MPG matters to you, but its NOT good for Hybrids!!!
Hybrid performance is a more complex than just the engine:
- cold air is dense thus increasing energy demands at higher speeds
- cold lubricants are viscus thus increasing energy spent moving the parts
- cold manifolds, engine blocks and catalytic converters require warm-up
- cold batteries need to be warmed up to operating temperature range

As for less efficient, gas only vehicles, they have energy to burn. In fact, that is their problem . . . they burn too much energy. The cold weather effects are less noticable as they are shelter behind their existing inefficiencies.

Bob Wilson
 
  #18  
Old 03-07-2006, 03:54 AM
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Default Re: Gas Mileage down? - Spring is coming

cold air is good for one thing only with respect to combustion engines- higher density...more oxygen per charge, nature's little turbocharger, in effect. But more oxygen requires more fuel to remain stoichiometric... lower FE.

Other than that, is saps efficiency everywhere, as bwilson pointed out. Additionally, the greater temp difference between outside and the engine block means exponentially more energy lost through the block walls instead of being put to useful work.
 
  #19  
Old 03-07-2006, 05:24 AM
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Location: Saginaw, MI
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Default Re: Gas Mileage down? - Spring is coming

This morning wasn't too good. 18F. Meh. Doesn't matter. I finally ordered a trailer hitch and a bike rack for my car last night. Should have everything ready for the weekend (fingers crossed). I'm going to try to fit in a ride or two. I need to get outside and exercise. I need that more than higher MPG right now
 
  #20  
Old 03-07-2006, 06:58 AM
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Default Re: Gas Mileage down? - Spring is coming

Any chance we're getting a break-in advantage due to the cold? Maybe a 'subzero cylinder hone' or a better bearing break-in that might lead to easier rolling during warm weather?

Just dreaming - anyway, it's almost over for this year, and next year I won't care, really I won't...
 

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