Buy the rims because you like them. Even if you made a 5% saving on fuel cost (which you will not) then you would have to drive over 150,000 Km to save $1,000 for wheels and you still have not factored in the cost of money. If you race a skyline then you already know about tyre pressures so keep them pumped up and find another excuse to spend.
Yes, what about it? I have to agree that lowering your suspension and driving in circles so your tyres rub on the guards will reduce your fuel economy. I have also observed that shooting oneself in the foot contains risk of personal injury. Are you having us on here Denham?
If you are asking will the tyres rub, that depends on how wide they are as well as on your suspension height decisions. There are other threads on that general question.
Found some fabulous deep dish rims in 20 inch but offset +45. Will this offset cause the rims to sit 2 far into the guards or will it enable me to lower the car so the wheels tuck in nicely under the guards and wont rub the tyres?
Deep dish wheels + tucked inside the guards is not very VIP, so i wouldnt bother getting expensive Fabulous wheels if thats the look you are after. Might as well get some cheap chromies from Tempe Tyres!
To get the flush look that you see on alot of the Japanese VIP cars, they use precise measurements, and a combination of Widths and Offsets.
The only problem is that the offsets that they usually go to are illegal in australia, and will get you castrated by other forum members... But if you want a conservative VIP look, this Celsior on the Fabulous site has 19x9 offset +36 and 19x10.5 offset +30 wheels