Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - how much does altitude affect MPG in a N\A diesel engine????

trooper Tdiesel · 05-11-2012, 01:17 AM

some info i copied from the other site.

Quote:

How to lighten up
Scroll down an it says you lose 3.5%hp per 1,000ft you climb. So if i did my math right, an say the n/a motor makes 60hp, you'll lose 2.1hp per 1,000ft. So at 6,000ft your losing 12.6hp, going from 60 horse, down to roughly 47/48. that isnt very many ponies, in fact your into gerbil territory there lol.

remember that's 60hp at max RPMs 4,200

its about 40hp at 3,000 rpms

using the 6,000ft number
that's 8.4 hp lossed from 40hp making about 32hp

and 95 torque at 2,200 rpms drops to 75.05

now lets try it saying an avrege of 4,000ft
the 60hp number drops 8.4hp

the 40hp number drops 5.6hp

the 95 torque number drops 13.3

so ok lets compare "ball park" mpg numbers...........
1,292 miles for the northern route.
1,154 miles for the southern route.
for a total difference of 138 miles, now....
that's the distance from the ends of where the two routes go there ways, and return to one another.

now using those mile numbers, ill figure 4 different MPG numbers that are quite possible.
32, 34, 36, 38

staring with the southern route.
32=36.0625 gal
34=33.94 gal
36=32.055gal
38=30.368gal

now the northern route.
32=40.375gal
34=38.00gal
36=35.888gal
38=34.00

so it only takes about a 3.9 mpg difference to make it brake even....

as wako as this sounds, i think its possible that its close to brake even.... to drive an extra 138 miles on a road that's flatter :shock: