Hi Markoz.
Thanks for reply,i have been messing with the cfg file,to try and get correct fueltank names and position corrected , and increased eng to 34000 and increased drag on flaps/aircraft , and moved cg fwd slightly , test flight yesterday , gave a better flight than day before , but failed to get to 50000ft , so need drag reducing a bit , and maybe a bit of increase in lift scaler , but FSX did not like the tanks renaming or adding the extra tank , so i will just have to play  around with fuel tanks that i have,regarding position and qty,to give correct fuel.
I have found a web site , which shows tank names and positions but not the qty , and going from info found sofar CSb52 driver has a shortfall on fuel qty.
And going from a schematic showing tanks there is in fact 13 tanks ,but it will i think be imposible to model this correctly.
The tanks from left wing to right wing are , left ext ,leftoutbd, main1,main2,ctrwing,main3,main4,rightoutbd,r ext.
On the body tanks from front to aft are named, fwd body ,then the ctrwing,then another fwd body,mid body,aftbody.
As you can see fwd body tank consists of two tanks eitherside of the cntr wing tank.
I think the airfile might need to be redone regarding fueltank names,inorder for the fsx to recognise the names , and i do not know or have the programe to do that,it is somthing CS would have to reply to or alter .
I would like to see this aircraft done in a pro version for the ones like me , who like the challenge of flying them like the real aircraft.
I have put fuel in one tank at a time , and found aft/mid body use FSX center3 fuel tank, so you can never use the fuel correctly,as per a post i have read on this forum over the correct use of fuel tanks/selection during a flight,to keep cg at correct limits over all phases of flight.
According to info about TOTAL FUEL QTY,cs52 driver is some 3173 gal short,
Regards alan. :(