Handling
The BMW 3 Series's rear-wheel drive layout likely gives it better dry traction than the TL; on the flip side, the TL's front-wheel drive layout likely provides better traction in rain, snow or ice.
The Acura and the BMW 3 Series have approximately similar tires.
With its tighter turning circle, the BMW 3 Series is definitely sprier than the Acura TL, something to consider if you do a lot of city driving; on the other hand, note that a vehicle with a tight turning circle may feel a bit twitchy on the highway.
Drivetrain
The Acura TL's engine isn't much more massive than the BMW 3 Series's.
Torque is the force that lets you accelerate quickly, and in this respect, the Acura TL isn't much more powerful than the BMW 3 Series.
Utility
Neither the BMW 3 Series nor the Acura TL has a marked advantage regarding seating capacity.
Convenience
The BMW 3 Series's fuel tank will need to be replenished a bit more often than the unit in the Acura TL.
You very likely won't have to visit your friendly gas station more often with the BMW 3 Series than with the Acura TL, as both offer similar mileage ranges.
Comfort
Taller drivers will markedly enjoy the extra head room in the Acura's front cabin compared to the BMW 3 Series.
The Acura TL is not particularly roomier for your passengers than the BMW 3 Series.
Dimensions
The Acura is a bit more ponderous than the BMW 3 Series.
The 3 Series's tank is roughly the same size as the Acura TL's, though the Acura TL's is somewhat more capacious.
The BMW 3 Series and the Acura TL compete for the same parking spaces.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs about the same to get the Acura to the dealership as the BMW 3 Series.
There frankly isn't much of a difference in gas mileage here, but if you must know, the BMW is somewhat more economical than the Acura TL.
When it comes to MSRP, the Acura TL doesn't cost much less than the 3 Series.
The Acura TL is substantially less costly than the BMW 3 Series as far as final cost.
Overview
The TL and the BMW have the same basic warranty.