Originally Posted by Bennett
I had to take a detour home today so my usual commute was swapped out for a highway drive for a few miles.
I found it incredibly difficult to get decent mpg. I'm not sure if it was simply all the traffic and the need to keep up or if my accelerator technique was all wrong. I've been doing ok on my regular roads to work (even taking into account two annoying hills). The car just felt "sticky" and didn't really want to drop down to lower rpms. Speeds weren't all that high (40-50 max), often more like 20-30mph if traffic was slowing. In the city at 20-30mph I'm happily getting decent mileage when the car is warmed up.
Once I was on my final leg home it was plain sailing. SoC was good the whole time. I'm wondering if the additional traffic just stopped me from doing any of the P&G, fake downshift or EVGlide techniques that I could use otherwise.
The difference was 35mpg on the highway run...50mpg for the country road segment. I'm wondering if I should be accelerating to a higher speed to coast more, rather than trying to micromanage the revs at the low end.
In any case, it further increased my hatred of rush-hour highway driving and makes me appreciate my 40-minute country commute even more
Wifey is away this weekend so I'm tempted to take it out for a spin and try a few miles on more open road at highway speed.
Car is a 2008 HCH-II.
It's very difficult to achieve high energy efficiency during rush
hour because of the speed and the traffic. Drafting/slipstreaming
and Driving With Load
(DWL) are the best hypermiling techniques
for driving faster than 55 mph (super highway). However, they can
become increasingly difficult to do as traffic gets more congested,
other drivers become more aggressive, and the overall traffic speeds
gets faster. P&G and EV modes are often not sustainable at speeds
over 55 mph.
Before you go onto they highway, make sure your tire pressure
is set to about 2 to 5 psi over the manufacturer's recommended setting.
+2 psi is for aggressive rush hour traffic while +5psi is for long distance
non aggressive turnpike hi speed traffic. 2 psi + recommended psi
will likely be more energy efficient for sudden and constant application
of the accelerator. My experience and others on prius chat has
been that as tires pressures are inflated at higher levels (e.g.
+7psi) highway FE drops ( my currently theory is that the
transfer of energy is less efficient because tire deformation decreases
as tire rigidity decreases with overinflation, the tire deformation
is necessary to maintain tread road traction during high speed