For the Fellahs that are posting out of state, don't mislead the OP if you don't actually know what the chain requirement are. in the State of California and Nevada, it is DOT's policy to use NO SALT or chemical road de-icers of any kind; only sand is dispersed to add traction because it is bad for the flora and fauna of the mountain if chemical de-icers are used. This is unlike the DOT policies back East or in the Midwest; plow rigs disperse de-icers almost after any road is plowed. As for highway 50, when it snows hard, the CHP (California Highway Patrol) and Caltrans slows (effectively stopping traffic) traffic and they come around your vehicle to physically inspect your sled's tires. If the road conditions have not deteriorated where it becomes hazardous in the manner where all season tires become ineffective, they'll allow cars to pass but traffic is seriously slowed because of the check point. If the snowy conditions are bad, a Officer or Caltrans rep will make you pull off into the shoulder and into a chain installation area that is designated. Only after chains are installed will you be released to proceed up the highway.
For those Fellahs telling the OP chains are not needed in the event it is very snowy, the OP would be stopped, questioned by the law enforcement authority, and if he is not carrying the right equipment, he will have turn around and drive back down the mountain to buy chains. Advising the OP of faulty information is not only ignorant, but it is a potential time waster for the OP. This is no way to treat this fellah.
Ray, look up the phone number to the CHP station in Tahoe and program it in your phone. The CHP Station in the Grapevine Pass, I call this number when I drive to Sacramento during the Chrismas holiday when it is raining because the CHP will tell you the protocol they are enforcing for bad weather.
Lastly, for the crowd that believes I don't know how water on gas works, think again. There is always a certain amount of water/moisture in gasoline. In freezing temperatures, it doesn't form into a nice and neat ice cube in the tank. The water will make the gas thicken because it is all mixed together. Next, the gas line from the tank to the fuel injector, that line is metal so it very susceptible to cold temperature and it is a small diameter line, perhaps .375 inches, OD. It is not the diameter of a garden hose. That small diameter line runs the length of the entire car exposed to outside temperature so there must be 15 or more feet of very small diameter fuel line. Moisture in the fuel line will thicken the gas in bitter cold temperatures. Add the fact there are tight turns in the fuel line, this adds to line restriction, thereby exacerbating the problem. If a car has been outside overnight for say 10 - 12 hours or so in bitter cold temps, and you all think a small fuel pump in bitter cold temps can move 15 or 20 feet of even slightly thickened fuel through a small diameter uninsulated metal fuel line and spray this fuel past an injector whose job is to atomize fuel through an extremely small opening, well then, you Fellahs know something I don't. I bought the t-shirt on this so I know first hand.