Diff ratio decision - ratio Vs tyre size Vs rpm figures please

[OzCuda]

Need to start making some decisions about things including what diff ratio to run.  If people have the data, I would appreciate a run down of the ratio you run, the tyre size at the rear and what rpm you are getting at say 60 mph on the highway.  Toying with running 3.55 with slightly larger than stock rear wheels but don't want to be revving too high and using too much fuel when touring etc.  Thanks.

[BlueStreak_Johnnie]

Tci has a little calculator that gives you the aprox. rpm for a given set up.

http://www.tciauto.com/tech_info/calculators.htm#0

Just plug in the numbers of what you have or want.



J.

[OUTLAW]

yes there are tons of gear calculators around but for the rest of the questions  I run 4:30 gears with 26 inch tall wrinklewalls and a 4 speed  around town it runs about 2500 at 40 and about 3500 at 60

[OUTLAW]

yes there are tons of gear calculators around but for the rest of the questions  I run 4:30 gears with 26 inch tall wrinklewalls and a 4 speed  around town it runs about 2500 at 40 and about 3500 at 60

here is a gear calculator
http://www.moparsa2z.com/web/archive/converters/Ring_Pinion_Calculators.htm

[OzCuda]

Hadn't thought about using a calculator and working back - thanks.  I was interested though in real-world set ups and what people were actually running, what your optimum cruising rev range is at 60mph (100kmh here) and general impressions.  My barracuda is probably going to see some longer trips to events and cruising on holidays so I need to balance between a bit of bottom end grunt and not having to mortgage the house to go for a drive with current fuel prices.