Speaking of mileage and the unholy myths out there

spidey07

No Lifer
Aug 4, 2000
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Just for giggles with all the BS floating around I got on the highway. Reset computer and traveled at 70 MPH. That gave me 28 MPG.

Reset again and held 85-90. That gave me 32 MPG.

Both tests were run over at least 20 minutes, only on freeway, on moderately flat terrain, with same accesories and little to no work from the heating/cooling system given that ambient temp equaled in car temp.

Don't believe the hype. Don't, don't, don't believe the hype. The revolution will NOT be televised.
 
Oct 9, 1999
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if you went back the opposite direction with a tail wind that can cause your mileage increase.

and 20 miles is nothing.. you got to do tank to tank.. over 100's of miles.

PS: at higher speeds wind resistance increases so i call shens!
 

imported_michaelpatrick33

Platinum Member
Jun 19, 2004
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4 miles per gallon more? That is statistically significant and I would call into question the controls of this study :laugh: . Were you drunk at the time? And yes I am kidding.
 

spidey07

No Lifer
Aug 4, 2000
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Originally posted by: TheGoodGuy
if you went back the opposite direction with a tail wind that can cause your mileage increase.

and 20 miles is nothing.. you got to do tank to tank.. over 100's of miles.

Same direction, just reset computer halfway through.

This is not an odd occurance, I've noticed this on my commute of 80 miles. higher speeds = increased mileage. It's all gearing. 85-90 is around 2800 RPM, the sweet spot.
 

Hyperlite

Diamond Member
May 25, 2004
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hmmm...is it an automatic or a manual? mabye a large hill @ 70mph in an automatic could encourage a downshift(s)?
 

spidey07

No Lifer
Aug 4, 2000
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Originally posted by: JulesMaximus
Are there any hills in Kentuckee?

Of course. It isn't as flat as Indiana, but my road is "moderately flat" Hilly in some areas (rivers), flat in others.
 

vi edit

Elite Member
Super Moderator
Oct 28, 1999
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Depends on the car.

I'm sure your TL with 6 forward gears fares a lot better than my 4500 pound brick of a truck with only 5.

I know there is a HUGE drop at 75MPH vs 55MPH with mine.
 

GagHalfrunt

Lifer
Apr 19, 2001
25,284
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Your tests are flat out wrong. There is no way your car gets better mileage as it goes faster. Simple physics proves that that's impossible. As speed increases wind resistence increases and fuel efficiency drops. It can't happen any other way.
 

vi edit

Elite Member
Super Moderator
Oct 28, 1999
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Originally posted by: GagHalfrunt
Your tests are flat out wrong. There is no way your car gets better mileage as it goes faster. Simple physics proves that that's impossible. As speed increases wind resistence increases and fuel efficiency drops. It can't happen any other way.

I wouldn't say it's impossible. Some cars may simply have a certain RPM range where fuel economy is better at. With 6 gears they may be more efficient at a higher speed than a lower one. Lower RPM's isn't always a good thing if the engine is bogged down.
 

spidey07

No Lifer
Aug 4, 2000
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Originally posted by: Hyperlite
hmmm...is it an automatic or a manual? mabye a large hill @ 70mph in an automatic could encourage a downshift(s)?

04 TL. Manual. But you're correct, 70 MPH on flat terrain is NOT a sweet spot for this car. You're between gears basically.

What I'm trying to demonstrate is the myth of driving fast decreases mileage dramatically.

I am serious when I say I get my best mileage at 85-90 and higher MPH. I measure it every single day.
 

sswingle

Diamond Member
Mar 2, 2000
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I get better mileage if i do around 80 as well. All this wind resistance talk is BS. Cars are built to be aerodynamic to some extent. Plus, there is the whole thing about gears that come into play.
 

spidey07

No Lifer
Aug 4, 2000
65,469
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Originally posted by: GagHalfrunt
Your tests are flat out wrong. There is no way your car gets better mileage as it goes faster. Simple physics proves that that's impossible. As speed increases wind resistence increases and fuel efficiency drops. It can't happen any other way.

I really do disagree. Depends on the gearing and the motor.

-edit- It's freeway driving, I rarely use more than 1/4 or 1/8 throttle at the most, only to climb a hill