#Piston

Pete writes:

Hey Sajeev, I got one for you.

Several engines nowadays are set up to operate on half their cylinders under light-load conditions. Would the design considerations for piston rings vary from those normally used for such cylinders that are only used part-time? The question arises in the context of a 2009 V6 Accord that is currently in the Honda dealer’s shop to have the piston rings replaced at the manufacturer’s expense to cure a continual oil consumption and spark plug fouling problem.

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?

Dave writes:

Hi Sajeev,

This is the second question I’ve asked on here, and while I didn’t even follow the advice I received last time and here I am again! Last time I was asking about a sporty car, and I ended up getting a 2007 Ford Ranger, 2.3L, 5 speed, with all of 35,000 miles on it. It is a regular cab with nothing extra on it, a real throw back, manual windows, no AC, a nice basic truck with nothing to go wrong right?

Wrong.