To be honest, I think that the fuel flow rate has gotten better too.
The only thing i can think of which offsets the pit stop strategy from 5 to 6 is the fact that racing tyres have gotten a lot better on real/normal/whateveritis option for the degredation. So basically we have gotten to where in an R18 at around 520HP, I can do almost the 11 lap stints on a tank, but unlike 5, i can probably double, or even triple stint tyres.
The problem, is the fact we cannot choose retain/no tyre change and add only fuel. This is where strategy would come into effect.
Do I stay on these tyres to shave a few seconds off of my pit stop? Or do i replace all four and gain more time on track?
Now I am relating all of this basically to the FIA/WEC's pit regulations, meaning only two men are allowed to touch the car at a time. Meaning that two tyres may be changed, and then another two, and then fuel can be added. In that instance, pit stops would be upward of 1-2 minutes (counting time only in the pit box) and could vary even more if you were only to take two tyres.
Another thing is, not all cars in the game have star/six pattern lugs holding the wheels. That alone takes about 2-3 seconds per tyre, and can be shaved off when purchasing wheels and then be applied while racing.
Here is what I think should be added into a pit options:
Tyres:
Wear: none/slow/normal/fast/very fast (slow could be removed)
Lug pattern: individual(meaning each players own wheel patterns)/center/pattern
Fuel:
Fill rate: slow/normal/fast ( i guess you would take 9.8m/s/s and divide that by 1.5 or multiply to get rates)
Tank limit: 0-100 Gal/L
Crew:
Crew members: 2/2+gass/4 (2 meaning the 2 men then gas, 2+gas meaning 2 men and gas, and four is current)
Position: waiting/jump out
Garage:
Drive in options: Crew pulls in/car drives in (this would probably be under ai control for ease{i just thought of the Codemasters F1 series and thought this would be a nice addition for tracks with garages})
Settings:
Speed: 15/25/35/45 (mph/kph)
Penalties: Entrance speeding/exit speeding/wheelspin out of pit box/Unsafe releases(collision must occur)
I think allowing the drivers to actually drive the car in all the way would be nice, but I also read that there could be legal issues with a driver being able to run over the crew, causing the player rating to go up to M possibly for violence. But then again, online interactions are not reflected by those ratings (at least in the US). So if the workaround would to be make the crew come out of the garage, then by all means do it..