ElTorrente

I drop it DOWN to 5th gear when rpm is LESS than 3000, to keep it above 3000. If I slow down a little bit, and rpms go below 3000, I'll drop it down to 4th to keep it above 3000. I only use the overdrive gear when I'm cruising at about 75mph or above.

The lower the gear, the lower the rpms can be without it lugging under acceleration. For instance, 2000rpms is no big deal at all if you're in 1st or 2nd gear. Obviously, to accelerate from those rpms in those gears isn't going to lug the engine much at all, because of the high ratios. Similarly I don't think being at 3000 in 5th gear is lugging much for "normal" acceleration, though I'd drop it to 4th if I was going to pass someone.

I don't actually think 2800 is necessarily "bad" in 6th gear anyway, IF you are just going to cruise along slowly without accelerating much or going up hill - but I like it being more responsive in 5th at those relatively low speeds. It's just a tiny trade-off in mpg, and more peace-of-mind to myself, who is an anti-lugging type of guy. I like doing what I can to keep my pistons and cylinders clean.

I also like to practice heel/toeing and engine braking for a bit when I'm slowing down to a stop or from highway speeds, so I can create a suction and pull blow-by gasses from beyond the rings to burn it off and keep my internals clean.