- Does Toyota Camry 2015 -2017 (SE) use aluminum wheels?
Depending on the option package, the Camry could come with either aluminum or steel wheels.
- Are they produced using casting or are they forged?
Most OEM wheels are going to be castings and not forged. You have to get into the limited markets in order to find wheels of the forged varieties as OEM. Like Solar Mike tried to state, it all comes down to cost. A Camry is not a "top of the line" vehicle, so you most likely would not see it roll off the assembly line with a forged wheel. Even the Lexus (the up-brand Toyota) would most likely not see forged wheels.
- Are steel wheels safer than these alloy wheels?
Safety of wheels is usually not an issue. Wheel failure is not usually a cause for accidents. It's usually something external which causes a wheel to fail, such as an accident or road hazard.
NOTE: There are safety reports which state 35% +/-11.4% of crashes are caused by tire/wheel failure, though they do not seperate out how much of each is the cause. Since tires are a wear item, it seems most likely (IMHO), the tire is by and large the greatest part of these failures which cause the crashes, either through the tire being worn out or improper inflation. This article also shows as Tires/Wheels being the #1 mechanical reason for crashes, but then only show tire blowouts and worn tires in the causal section. This article talks about the dangers of wheel separation from the vehicle as a larger issue than most would think. While a dislodged wheel flying from one vehicle to another is quite dangerous, this is caused not from wheel failure, but rather from the failure of wheel lugs/nuts (improper wheel installation), wheel bearing failure, and axle separation as the causes, not from failure of the wheel itself. Even split rims don't usually have issues once everything is seated properly during tire installation.
- What type of wheels have more chances to be cracked?
A cast wheel will crack well before a steel wheel would. This is inherent in the design. The steel is much more flexible than is cast aluminum. But really, unless you are in an accident or there's a very severe road hazard (pothole or curb), there's really no worry for either to happen.