Interesting...

[TheMase]

FORMULA ONE
Engine size/type 3-liter V10
Horsepower Approximately 800
Top racing speed Approximately 225 mph
Maximum RPM Approximately 18,000
Fuel Unleaded racing gasoline
Engine turbocharging Forbidden
Tires Four circumferencial grooves
Minimum weight 1,322.76 pounds with driver
Maximum height 37.43 inches
Maximum width 70.92 inches
Forward gears Four to seven


INDY RACING LEAGUE
Engine size/type 3.5-liter V8
Horsepower Approximately 650
Top racing speed Approximately 240 mph
Maximum RPM 10,700 (with rev limiter)
Fuel Methanol
Engine turbocharging Forbidden
Tires Slicks
Minimum 1,550 pounds without driver
Maximum height 38 inches
Maximum width 78.5 inches
Forward gears Six


There ya go, Indy cars are faster, but I would imagine with the Indys being wider that the Formula One cars could be faster overall...

 

[Perrin]

Indy cars may have a higher top speed but only when they are running an oval racing set up.

The F1 is far more advanced technologically. Put them side by side on any racing circuit (bar ovals) and the F1 will win hands down. They have far superior acceleration, braking and handling capabilities.

Cheers

 

[The Ewok]

The F1's and the Indy/Cart's raced at one of the same circuits not long back at and the F1 car was seconds and seconds infront in terms of lap times

 

[GOALden Hawk]

Michael Schumacher said if an F1 car was setup just to run straight for 2km it would reach between 700 and 800km/h!