#Bogging

Pat writes:

Hi Sajeev,

I have a question about driving style that I’d like to pose to you and the B&B. Part of my highway commute is a steady 2 mile grade. With a running start of 75 mph, my 2007 Mazda B2300 slows to about 62 mph by the top of the hill when I keep it in 5th gear, with the engine turning about 2000 rpm. I can maintain 70+ if I drop into 4th and floor it, but I’m a cheapskate at heart. My question is, is it really more efficient to lug up the hill in top gear, or am I just kidding myself and doing irreparable damage to my engine?