Our '98 35' Santara got less than 7 and usually 4 to 6.5. It was a tag axle unit and usually towing and '95 Honda Odyssey on a dolly. Not much, if any improvement with the Banks kit but it was nice to have the extra power.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '05 Odyssey