The Cayman has standard front seat side-impact airbags and head airbags, which act as a forgiving barrier between the passengers and the door. Combined with high-strength steel door beams this system increases protection from broadside collisions. The Viper doesn't offer side-impact airbags or side airbag protection for the head.
To prevent wheelspin and loss of control under poor traction conditions, full range traction control is standard on the Porsche Cayman. The Dodge Viper doesn’t offer traction control.
The Cayman has standard Porsche Stability Management (PSM), which uses the antilock brake hardware along with powerful software and additional sensors to detect the beginning of a skid. PSM then intervenes by automatically applying the brake at one appropriate wheel, preventing a skid. The Viper doesn’t offer skid prevention. A National Highway Traffic Safety Administration study showed that skid control systems reduced single-vehicle car crashes by 30%.
The Porsche Cayman offers Daytime Running Lights to help keep it more visible under all conditions. Canadian government studies show that driving with lights during the day reduces accidents by 11% by making vehicles more conspicuous. The Viper doesn’t offer Daytime Running Lights.
The Cayman offers optional parking sensors to help warn drivers about vehicles, pedestrians or other obstacles behind their vehicle. The Viper doesn’t offer any parking assist system.
Both the Cayman and the Viper have standard driver and passenger frontal airbags, front seatbelt pretensioners and four wheel antilock brakes.
The Cayman comes with a full 4 year/50,000 mile basic warranty, which covers the entire car. The Viper’s 3 year/36,000 mile basic warranty expires 1 year and 14,000 miles sooner.
The Cayman comes with free roadside assistance for 4 years 50,000 miles. Porsche will send help if you run out of gas, need a jump start, lock your keys in or need any assistance on the road. Dodge doesn’t give free roadside assistance for the Viper.
The Cayman’s corrosion warranty is 5 years and unlimited miles longer than the Viper’s (10/unlimited vs. 5/100,000).
For smoother operation, better efficiency and fewer moving parts, the engines in the Cayman have an overhead cam design, rather than the old pushrod design of the engine in the Viper.
J.D. Power and Associates rated the Cayman second among compact premium sporty cars in their 2008 Initial Quality Study. The Viper isn’t in the top three in its category.
J.D. Power and Associates’ 2008 Initial Quality Study of new car owners surveyed provide the statistics that show that Porsche vehicles are better in initial quality than Dodge vehicles. J.D. Power ranks Porsche first in initial quality, above the industry average. With 54 more problems per 100 vehicles, Dodge is ranked 27th, below the industry average.
The flat cylinder configuration of the boxer engine in the Cayman lowers its center of gravity, enhancing handling stability. The Viper doesn’t offer a boxer engine configuration.
The Cayman has almost a gallon more fuel capacity than the Viper (16.9 vs. 16 gallons), for longer range between fill-ups.
The Cayman’s brakes have 20% more swept area (the area covered by the brake pads) than the Viper (722 vs. 603 square inches), so the Cayman has more braking power available.
The Cayman S offers optional heat-treated ceramic brake rotors, which last ten to twenty times as long as conventional cast iron rotors, don’t rust, don’t fade during repeated high speed braking, and their lighter weight contribute to better braking, handling and acceleration. The Viper doesn’t offer ceramic brake rotors.
The Cayman stops much shorter than the Viper:
80 to 0 MPH
Road & Track
70 to 0 MPH
Car and Driver
For better ride, handling and brake cooling the Cayman offers optional 19 inch wheels. The Viper’s largest wheels are only 18 inches in the front and 19 inches in the rear.
The Cayman S goes through Road & Track’s slalom 4.5 MPH faster than the Viper Coupe (74.2 vs. 69.7 MPH).
For better maneuverability, the Cayman’s turning circle is 4.1 feet tighter than the Viper’s (36.4 feet vs. 40.5 feet).
The Porsche Cayman may be more efficient, handle and accelerate better because it weighs about 400 to 450 pounds less than the Dodge Viper.
The Cayman is 3.5 inches shorter than the Viper, making the Cayman easier to handle, maneuver and park in tight spaces.
To almost totally eliminate engine vibration in the passenger area, the Cayman has liquid-filled engine mounts. The liquid helps further dampen engine harshness. The Viper uses conventional solid rubber engine mounts.
The design of the Porsche Cayman amounts to more than styling. The Cayman has an aerodynamic coefficient of drag of .29 Cd. That is significantly lower than the Viper (.38). A more efficient exterior helps the Cayman go faster and keeps the interior quieter. It also helps the Cayman get better fuel mileage.
The Cayman has 1.3 inches more front headroom and .6 inches more front legroom than the Viper.
When three different drivers share the Cayman, the optional memory system makes it convenient for all three. Each setting activates different, customized memories for the driver’s seat position, outside mirror angle and climate settings. The Viper doesn’t offer a memory system.
The Cayman’s front power windows open or close with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside of the car. The Viper’s power windows’ switches have to be held the entire time to close them fully.
The Cayman’s standard power window controls are mounted on the armrest for easy access. The Viper’s available power window controls are spread out on the center console where they can’t be seen without the driver completely removing his eyes from the road.
If the windows are left down on the Cayman the driver can raise them all using the key in the outside lock cylinder; on a hot day the driver can lower the windows. The driver of the Viper can only operate the windows from inside the vehicle, with the ignition on.
The Cayman has a standard locking fuel door with a remote release located convenient to the driver. A locking fuel door helps prevent vandalism, such as sugar in the tank and fuel theft. The Viper doesn’t offer a locking fuel door.
The Cayman’s optional wipers adjust their speed and turn on and off automatically according to the amount of rainfall on the windshield. The Viper’s manually variable intermittent wipers have to be constantly adjusted.
Heated windshield washer nozzles are standard on the Cayman to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The Viper doesn’t offer heated windshield washer nozzles.
To improve rear visibility by keeping the rear window clear, the Cayman offers an optional rear wiper. The Viper doesn’t offer a rear wiper.
In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The Cayman offers available headlight washers to keep headlight output high. The Viper doesn’t offer headlight washers.
The Cayman’s standard side window demisters help clear frost or condensation from the side windows in the winter. The Viper doesn’t even offer side window demisters, so the driver may have to wipe the windows from the outside to gain side vision.
The Cayman’s outside mirrors include heating elements to clear off the mirrors for better visibility. The Viper doesn’t offer heated side mirrors.
The Cayman’s optional rear and side view mirrors have an automatic dimming feature. This mirror can be set to automatically darken quickly when headlights shine on it, keeping following vehicles from blinding or distracting the driver. The Viper doesn’t offer the luxury of automatic dimming mirrors.
The Cayman’s optional heated front seats keep the driver and front passenger extremely comfortable in the winter. The Viper doesn’t offer heated seats.
The Cayman’s optional air conditioned front seats cool the driver and front passenger and help take the sting out of hot leather in Summer. The Viper doesn’t offer air conditioned front seats.
The Cayman’s optional automatic temperature control maintains the temperature you set, automatically controlling fan speed, vents and temperature to maintain a consistent, comfortable environment. The Viper doesn’t offer automatic air conditioning.
A built-in pollen filter with a charcoal activated canister removes pollen, exhaust fumes and other pollutants from the Cayman’s passenger compartment. This helps prevent lung and/or sinus irritation, which can trigger allergies or asthma. The Viper doesn’t offer a filtration system.
To help keep the driver’s hands on the wheel, the Cayman offers optional steering wheel controls for the radio. The Viper doesn’t offer steering wheel audio controls.
Insurance will cost less for the Cayman owner. The Complete Car Cost Guide estimates that insurance for the Cayman will cost $944 to $1120 less than the Viper over a five year period.