Why is there such a lag on Speed TV, compared to the live leaderboard on nascar.com?

May be...

They are rarely in sync with each other.

Probably just the satellite broadcast. I have a TV on rabbit ears on my computer desk at home and when my DirecTV is on the same local channel in the family room, the satellite is atleast 20 seconds or more behind the rabbit ears.

I'm not sure if this is the reason but I remember a while back when Dale Earnhardt Jr said on TV "That ain't 'Sheet'" there was also the incident where one of Janet Jackson's boobs got loose on national TV and stations decided to monitor what was broadcast in order to keep drivers from saying things on TV that was against the FCC regulations. The FCC was pretty hot about the Janet Jackson boob thing during the Superbowl I believe it was and NASCAR didn't want to get an FCC fine so they put a time lag on the broadcast. FOXtrax on FOX is the same way. It is ahead slightly of the actual TV broadcast. It allows TV stations time to bleep unwanted material.
http://www.people.com/people/article/0,,...

http://www.redorbit.com/news/general/920...

http://query.nytimes.com/gst/fullpage.ht...

It started with the Janet Jackson thing and then after Dale Jr made his slip stations started the time lag.

nascar.com has their priorities in order

That is because they do the broadcast in a way to show almost every car. When they go to commercial they pause the broadcast.

I'm watching the live leaderboard at the same time, and it seems like Speed TV is 4 cars behind.

It's actually a combination of things.

#1----Generally the broadcast has anywhere from a 5 to 10 second
delay to protect against foul language, bad crashes where things
shouldn't be seen by the public, or other things that the FCC
would ding a network over.

#2-----Speed usually pauses the coverage during qualifying so that
all the drivers can be seen qualifying although they do
sometimes skip over the lesser known one car teams.
From what I hear they do not do this during live races (trucks)

#3------Speed is not as fast as they claim to be --LOL!

There's a 5 second delay now--thank-you Janet Jackson!coreldraw cdr viewer