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Old 05-16-2019, 05:30 PM   #13 (permalink)
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Join Date: Mar 2014
Location: SUNNY Sequim, Wa
Posts: 238

Cavalier of D00M - '05 Pontiac GTO LS2 T56
90 day: 23.2 mpg (US)

The New One - '10 Toyota Prius II
90 day: 51.55 mpg (US)

Chick Magnet - '91 Geo Metro 3cyl/5sp
90 day: 48.07 mpg (US)
Thanks: 79
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Originally Posted by Hersbird View Post
I agree, I think it is more a result driven by want. You want it to do better at the higher speed so the testing never gives the lower speed a real chance at success. More speed takes more power, more power takes more fuel, it's just physics. At speeds under 45 with different gearing and such where aero doesn't have as big of an effect I can see it, but once the car is in it's highest gear whatever that just off idle rpm is will be it's highest economy. If there was some problem with the tune or motor, again possible, maybe you are overcoming a vacuum leak or rich idle condition. Tuned for economy and in perfect mechanical condition, top gear, just off idle.

with TALL gearing, slow speeds arent going to work
below 45 in 6th gear, my GTO is below idle
the car works alot less at 1900rpm

I've done the same 300 mile trip from Silverdale, Wa to Cresswell, Oregon over 50 times in the same car
I was averaging 27-28mpg trying to keep my speeds down in the 60-65mph range, and was able to achieve 32-33mpg on the trips I could run @75mph
I'd call that noticable
2005 GTO 6.0 V8 (600hp)

1991 Geo Metro 1.0 3/5 base

2010 Prius II (replaced 2001 Tahoe 5.3 V8 April 2014)

1994 F-350 7.3 TurboDiesel (Rollin' Coal)

Last edited by KrautBurner; 05-16-2019 at 05:50 PM..
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