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Old 06-04-2018, 11:37 PM   #9 (permalink)
oldtamiyaphile
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Join Date: May 2009
Location: Australia
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UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 44.93 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 32.34 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
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Mitsubishi
90 day: 36.59 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 22.37 mpg (US)
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When you calibrate an OBD gauge, you essentially tell it "this was my fuel consumption for my average engine speed/load last tank.

Change your average engine speed/ load (even just turn on the A/C) and your calibration goes out the window. This makes it difficult to compare driving styles.

If you take your city calibration and go on a highway run, you might be out by 10%, which is not uncommon on the cars I've got. Accelerating with fuel enrichment, likewise won't register on a system that only measures air.

I drive my Renault all city, but super consistently, last 3000 miles worth of fill ups all within 1 mpg, which gives the SGII an easy life - even then I'm lucky if SGII is within 10% (+/-5%). I know that on a long highway trip, the SG becomes little more than a guess o meter.

By comparison, a Guino that measures fuel, rather than air was able to find the BSFC sweet spot on an older vehicle that I had, a nice dip in consumption right at 80km/h, which of course became my cruise speed.
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Last edited by oldtamiyaphile; 06-04-2018 at 11:53 PM..
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