# How much gas am I saving over 1 km if revs per minute drop from 2400 to 800 whil

1. 79
Teresa Schultzposted 7 years ago

How much gas am I saving over 1 km if revs per minute drop from 2400 to 800 while I'm driving?

Let's say I'm travelling at about 80 km an hour and the needle on my revs per min guage shows 2400 revs per min. Then I approach a nice and steady very long gradual downhill, and I put my gears into neutral and "freewheel" for one kilometre, at 80 km an hour, with my revs guage showing 800 revs per min the whole km.

Let's also say that at 80km an hour, at 2400 revs per min, gas costs me \$0.15 for 1km of travel.

Now can I really say that  "freewheeling" 1km at 80km an hour, at 800 revs per min instead of 2400 revs per min saves me \$0.10 for that 1 km, or is there more to it than that?

2. 90
arksysposted 7 years ago

yep you can say it's freewheeling ... 800 rpm is the idle speed of an engine so even if you are standing on a traffic light your rpm will be 800... the higher you go in rpm the more fuel your vehicle will consume. i'm not sure how much exactly you will save in cash but you'll definitely be saving money.

i also remember watching a program once, in which they carried out an experiment on a custom circuit to check what kind of driving habit is better when you're running out of fuel to get the farthest. results showed that if you drive "like a granny" you'll get an extra km or two in a gallon.

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