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Old 06-11-2019, 02:14 PM   #5 (permalink)
mpg_numbers_guy
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Join Date: Feb 2018
Location: VA
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Toby - '13 Toyota Prius C
90 day: 61.95 mpg (US)

Daz - '15 Mazda 3 iTouring w/ Tech Package
90 day: 38.2 mpg (US)
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Safety first, always!

Try starting your descent at a lower speed. On my drive home, I have a steeper hill, then a steep downhill, then a right turn with a slight uphill about 100 or 200 feet right after the bottom of the steeper hill (2 way stop, I don't have to).

I generally downshift from 5th to third, keep engine load at best BSFC (70%-80% load) and allow my speed to bleed off from 35 mph down to 20-25 mph, then just before the crest of the hill I kill my engine, and am down to 15 mph by the top of the hill, then I roll down the hill and by the time I'm at the bottom (there's a small flat after the hill before the turn) I'm usually at around 20 mph by the time I make the turn. I typically am able to make the turn without using brakes (and then it's 2nd gear half throttle to 30 up the hill, then EOC the next half mile into my driveway).

The key is to be at the slowest possible speed at the crest of the hill. The lower the amount of fuel you use to climb the hill, the less kinetic energy you will have at the bottom that must be wasted either in brake heat or tire wear.

Also keep in mind traffic behind you. My drive home is typically past 10 PM at night when there is pretty much no traffic. Going that slow on the other side of a hill is not safe in heavily trafficked areas.
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2013 Toyota Prius C 2 (my car)


2015 Mazda 3 iTouring Hatchback w/ Tech Package (wife's car)
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