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Old 06-19-2021, 10:22 AM   #35 (permalink)
AKA - Jason
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Join Date: May 2009
Location: PDX
Posts: 2,868

Adventure Seeker - '04 Chevy Astro - Campervan
90 day: 17.3 mpg (US)
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I trust calculated fuel economy more than a computer over long periods of time and lots of fill ups. I trust the trip computer more than the fuel pump on a single fill-up. I've had 4 vehicles now with trip computers that show fuel economy and they have all be very constant. Yes, they might be a little off from the long term calculated fuel economy but they are constant. It is very common for my fuel logs to show the calculated fuel economy high on one tank then low on the next tank. I use calculated fuel economy to know the correction factor for the computer.

I'm not saying they are biased - I'm saying their method isn't scientific or repeatable.

I have a 2014 Jetta TDI. On long uphills I don't just let the computer do it's thing and select the gear. Not only does it hunt back and forth between gear which is annoying but it selects one gear too high. Looking at the instantaneous fuel economy it is more efficient to manually select a gear lower and raise the RPM near peak torque instead of lugging the engine and relying on more boost and fuel.

I've driven plenty of turbo engines and have had no issue beating EPA numbers. Accelerate up to speed with moderate throttle then stay out of the boost. Look ahead and adjust accordingly. That is all it takes.

People that complain about fuel economy with turbo engines are likely on / off / on / off / on / off the throttle. SO many people don't look past the car in front of them and just ride their bumper and are constantly braking and accelerating.
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