How much KM's do I have once the gas light goes on , on a 92 sc purrrfectly running with straighpipe from the cat back(sig car).

Depends on the mileage you get /driving style.

I filled up my car on Monday and as I pulled into the the fuel station the gas light came on, it took 17.9 gallons to fill the tank and the tank holds 20.6 gallons. That leaves 2.7 gallons in the tank, my car is currently stock, I drive it pretty conservatively and almost all of my driving occurs on the highway. I have an average fuel economy per tank of 23.8mpg. So at that average mpg I had 64.26 miles left in the tank before I needed to start walking.

Converting that to km is 103.416 km to empty. Now no fuel pickup is going to get every last drop and since I haven't carved up a SC fuel tank to see how low the pickup goes I can't give you a quote on how much of the 20.6 gallons you can actually get.

It is still best not to run it that low and I usually fill up much earlier, just got busy and let it slip my mind for an extra day or two.

I would say around 50 miles or 2 gallons of gas remaining...

^^^yes you have QUITE a bit left once the light goes on, 2 gallons seems about right from my experiance.

ive been driving for the past 2-3 days around the city with my light on, ill get some gas in the morning ...maybe lol