Jun 18, 2005. Oddometer: 1,085. Location: Tulsa, Oklahoma. I'm looking at a 890 Adventure R as more of a lighter do-it-all adventure bike for both off-road for me and light touring with my wife. I would love to hear current owners' thoughts about occasional sport-touring. I realize every bike is a compromise but the engine and suspension seem I had a 2106 1290 SA 42 mpg to 48 mpg depending on Terran etc. So on the downside 340 miles or so. The 1290 Adv R has a roughly a six gallon tank. So 250 miles or so range for the 1290 Adv R . The 790 Adv R has a 5.3 gallon thank my first tank was 55 mpg my next tank was 52 mpg . So your 250 plus mile range for the 790. gXBGEjg.