10 to 12 mpg improvement is the same as 30 to 60 mpg

[NachtRitter]

Originally Posted by jamesqf

Two different issues, and let's not argue about metric. Measuring fuel consumption in your inverted "liters per 100 kilometers" fashion just doesn't make sense, and that lack of sense is the same* whether it's quarts per 100 miles, gallons per league, or whatever. If I know that I get 70 mpg, and it's 350 miles to where I want to go, I know instantly the useful fact that I will need at least 5 gallons to get there. Give me that same number in liters/100 km (or gallons/100 miles) and I have to do some math to get a useful answer.


*Then there's the other senseless thing about your l/100 km: that it uses 100 km instead of just 1 km, or 1000 km. Supposedly the point of the metric system is to have units scaling by factors of 1000, yet this breaks that.

A matter of perspective, again. Possibly a more realistic value of 25mpg gives 4g/100mi. So a 350 mile trip is an "easy" 4 * 3.5 = 14gallons. And a 25mpg (or 12.5mpg which is 8g/100mi) is more in the range of Average Joe Public's typical ride.

But I agree when it gets into the 60mpg or 70mpg range, then the g/100mi value is a more difficult one to do simple math on... 1.67 or 1.43?? I personally can't figure out 1.43 * 350 easily in my head... then the MPG value makes more sense.

[gone-ot]

...sorta like the difference between dividing by 0.5 (Y = X/0.5) versus multiplying by 2 (Y = 2*X), etc.!

[NachtRitter]

Yes, exactly!

[NeilBlanchard]

The percentage saved is not as important as the quantity used, in my opinion.

A 12MPG vehicle burns 8.33 gallons in 100 miles, and a 60MPG vehicle burns just 1.67 gallons in 100 miles.

Or to put it another way, with a 15 gallon tank, the 12MPG vehicle travels 180 miles, and the 60MPG vehicle travels 900 miles.

[Fat Charlie]

Originally Posted by Old Tele man

...sorta like "...furlongs per fortnight..."?

That's just how they measure speed and while those aren't common measurements down here, the thinking is the same. MPH, KPH or FPF all measure the same thing in the same way. What's messed up is claiming that bales of hay per 100 furlongs is a good way of measuring the FE of your horse. Furlongs per bale makes more sense.

[gone-ot]

Originally Posted by NeilBlanchard

The percentage saved is not as important as the quantity used, in my opinion.

A 12MPG vehicle burns 8.33 gallons in 100 miles, and a 60MPG vehicle burns just 1.67 gallons in 100 miles.

Or to put it another way, with a 15 gallon tank, the 12MPG vehicle travels 180 miles, and the 60MPG vehicle travels 900 miles.

...that's how *I* look at / define FUEL ECONOMY in my mind, too -- less fuel.

[tortoise]

Originally Posted by Old Tele man

...that's how *I* look at / define FUEL ECONOMY in my mind, too -- less fuel.

You, and many others on this thread, seem to be arguing against a position that nobody has expressed. Nobody said 12 mpg is better than 60 mpg.

[Flakbadger]

Originally Posted by NachtRitter

And a 25mpg (or 12.5mpg which is 8g/100mi) is more in the range of Average Joe Public's typical ride.

Lol, not in Portland my friend. Everyone here thinks it's necessary to have an SUV or an F-2150

Well okay maybe you're right, I just thought it was funny!

[ecomodded]

My idea pitched again, the suggestion of quarts per 100 mile. 50 mpg would read as 8 q. per 100 miles,
a car that gets 10 mpg would read as 40 quarts/100mile.
Actual easy to understand once you look at the simplicity of the math.

[NachtRitter]

Originally Posted by Fat Charlie

That's just how they measure speed and while those aren't common measurements down here, the thinking is the same. MPH, KPH or FPF all measure the same thing in the same way. What's messed up is claiming that bales of hay per 100 furlongs is a good way of measuring the FE of your horse. Furlongs per bale makes more sense.

Hmmm... that's a good point... maybe we should be looking at hours/100mi instead of MPH... then if you know you are averaging 1.75hrs / 100mi (about 57MPH) it would be really easy to figure out how long it would take to drive 400 miles... 1 3/4 = 7/4 so it's 7/4 * 4 = 7 hours (badabing, badaboom).