It's all about what you're use to. Back on my old computer I had 15 FPS max, 5 with a full grid, on a 1024x768 with a joystick. Adimittedly, I was shit, but I played LFS for 2 years this way and enjoyed it enough that I was willing to deal with the terrible framerate.
Nowadays I have 100+ FPS consistently and 50 or 60 with a full grid, 3840x1024, and a nice wheel and pedals set. In the rare instence my computer dips below 40 fps because of something in the background, I can't deal with it. In fact, I can't even imagine how the hell I wasracing while running single digit framerates.