Quote:
Originally Posted by Tahoe_Hybrid
i tried going slower just a little bit but it wastes more gas
whats going on here i was going normal speed gets me about 1819 upwards of 22 but going a bit slower gets about 1516mpg

* All internal combustion engines will experience some road load' at which they are operating at their highest thermal efficiencies, and lowest brake specific fuel consumption ( BSFC ).
* Typically, your Tahoe would see its highest possible mpg at around a 'constant' 35mph.
* And that's based upon being : fullywarmed up ( driven @ 50mph for at least 50miles ), tires properly inflated, level road, no curves, dry, calm, no slowing, no accelerating, just a steady 35mph.
* Member AeroStealth tested his 2014 Ford F150, Crew Cab 4X4, 6.5ft bed, 6,000pounds curb weight plus passengers :
 18mpg average, stop and go city driving
 18mpg @ 62 MPH consantspeed highway
 36mpg @ constant 35 MPH highway

I just ran the numbers for AeroStealth's 2019 Chevy BOLT:
* 35 MPH road load hp= 5.4771, @ 4.08 KW
* 60 MPH road load hp= 17.1393 @ 12.78 KW
* 70 MPH road load hp= 24.9446 @ 18.62 KW
* 80 MPH road load hp= 35.0343 @ 26.13 KW
* 90 MPH road load hp= 47.7342 @ 35.61 KW
* 95 MPH road load hp= 55.1651 @ 41.15 KW ( 1mph over top speed )

1) The rolling resistance power requirement is increasing arithmetically (linearly ) with road velocity.
2) While the aerodynamic power requirement is increasing geometrically, as a cube function of the road / air velocity.