The last time I looked, there were 153 options you can choose from on your new 911 Carrera. You can't specify them all individually, as choosing some means you can't have others - unless you want several sets of wheels or a wood and carbon-fibre hybrid interior with yellow seatbelts on one side and red on the other. But if you could, the possible permutations of 911 would add up to a mind-melting 9.6 trillion subtly different models. That's nearly 1,610 distinct 911s for every man, woman and child on Earth.

But, as ridiculous as that sounds, that figure apparently still isn't enough for Porsche. Which is why it's just launched the 911 GTS. Slotting, according to the Zuffenhausen massive, into the 20-model 911 hierarchy (21 if you include the sold-out Sport Classic) above the Carrera 4S and beneath the Targa 4, the GTS Coupe and Cabriolet are forgivable additions to the dizzying line-up as they are, quite possibly, the best-value 911s you can buy.

Rumoured to be the last of the current 997 model before the switch over to the new (and naturally nearly identical) 998 later this year - but there's sure to be a few more specials in the works - the GTS offers perhaps the best performance-to-price ratioof any 911 on sale today. It's still no budget-priced bargain, but when you drill down into the GTS's standard specification and see what it would cost to spec a standard Carrera Sup to the same level, you start to see the point.

Let's start with the engine. The standard £74k Carrera S gets 385bhp and 310lb ft to play with. The only Porsche-approved way of getting that number to match the GTS's 408bhp, is to specify the £8k+ Powerkit option. So the price of your S would climb to £82k.

Now the wheels. The S comes from the factory with a set of 19in Carrera S II rims. To get the centre-locking RS Spyder wheels as worn by the GTS would set you back a further £2,300 and a grovel to your salesman as they aren't strictly available from the standard spec list. If you wanted them in black, that would be another grand. The subtotal for your GTS-chasing S now rises to £85.5k.

And we're not finished yet. The GTS's Sport Design front end will cost you another couple of grand. To get the wider Carrera 4 rear end the GTS wears as standard will, for the sake of argument, sting you for another couple on top of that. Let's say four and a half grand in total for bodywork. Which brings the running total to a round £90k.

To complete your mock GTS, you will have to spec the Alcantara interior and Sport Design steering wheel from the not-at-all-cheap Porsche equipment catalogue. That's another three grand of your hard-earned if it's a penny. So the final price after that nit-picking marathon, brings your once humble Carrera S to a grand and change short of £95k. That's £8,000 more than a 911 GT3.

Want to know the GTS price now? It's £76,758.