I have heard that the ideal rpm range for a Harley is from 25 to 3. Best for acceleration, engine likes it there, and best for gas mileage? Does this hold true for 09s and/or is this even true? Any other thoughts on ideal rpm? Thank you!
My admittedly limited experience says their engines are very happy in the 2500 to 3000 rpm range. I'm talking factory stock 08/09 Ultra Classics here. As for what's best for acceleration or gas mileage? The bike felt strongest between 3500 and 4500 rpms, especially any gear below 5th. As for gas mileage? There's so many factors that can effect that. Weight, winds, riding habits, topography, bikes condition, etc. I rented an 08 UC and spent a couple of days in the Texas Hill Country west of Austin and San Antonio. I had no problems getting into the low 40's with several tanks that ran 42 to 43 mpg but that was averaging 55 to 65 mph. I had one tank that was primarily freeway running, on the cruise control at 75 mph against a 10 to 15 mph headwind. That tank brought home a little over 33 mpg so it all depends. Keep the engine below 3000 rpm's and your right wrist level with or above the handlebar and you'll do pretty good. Engine above 3k rpms and your wrist below the bar most of the time and you'll pay the price! There aint no free lunch.
My 88 electra glide is the same. If I roll onto the throttle coming out of a corner & Im at 2000 rpm, my bike starts calling me "fat bastard"! it likes 2500 & up.
I usually like to have the bike at or around the 3K range no matter what gear I'm in that way if I need a little more throttle, I know the power is there. As for gas mileage, I would have got a Yaris or Focus if I was worried about that.
That rpm is the sweet spot for a stock or nearly stock engine.All engines have one no matter how it is built.You will always want the sweet spot in the cruise speed,final drive gearing will put it there.
I just had a 98" big bore with a S&S 510 cams installed on my 05.I have to say between 2900 and 3200 is my sweet spot now.It seem like the engine is more at ease at that rpm. As for as mileage go's.34 in town low to mid 40's highway.