The next 5 Series of BMW may take three to four years to appear, but its mechanical details have begun to emerge.

According to these details, the BMW 5 Series has been codenamed as F10 and it will be available with new kind of turbo engines.

The 540i will feature a 3.0-liter inline-six twin-turbo, the 550i will have a V-8, 4-liter twin-turbo, while the M5 will also have a turbo V-8 instead of V-10.

You would find the hybrids with full dual-mode as well as with mild types.

In this 5 Series, the wheelbase will also be increased two inches, but with the use of small turbocharged engines and use of aluminum in the external panels some efforts are being made to keep the current mass. Similarly, there will be arm-controlled front suspensions instead of the MacPherson struts.

Now instead of platform, BMW is now talking of a backbone and this term is being used for suspension, firewall and floor in different wheelbases. This backbone will become the part of the F10, 09 7 Series, 6 series and Progressive Activity Sedan for 2010.

This backbone is being regarded quite versatile, but it has certain limits too, as it may be quite small to the four door coupe CS, whose production has been shelved because of excessive cost in these days of worldwide recession.