Autocar - First for car news and reviews

This next-generation Audi S4 could be the super-saloon that ends the German power wars.
Our spies have caught the 2010 S4 undergoing high-speed testing at the Nurburgring and sources suggest that there’s a supercharged 3.0-litre V6 under the bonnet instead of the current model’s V8.
Insiders tell us that Audi wants to reduce the weight and improve the fuel economy of its new S4, while offering performance that’s on a par with the current models.
Meanwhile, it looks as though the range...Read the full article

Why would they use a supercharger if they're looking to improve efficiency? 

NiallOswald:

Why would they use a supercharger if they're looking to improve efficiency? 

Because when you take it easy - supercharger hardly working, you have a "frugal" 3l V6 engine more economic than the current V8 that is especially thirsty when used least - in city driving. However the supercharger can press some extra air into the cylinders when needed, doing so taking in at least as much air as the V8. Air that is needed to burn the fuel that gives you similar performance as the V8 with a smaller, relatively more frugal engine. So the largest difference is efficiency is not there when driven hard, but during those times you are using lots of fuel just to keep the engine running... like most of time in real world driving (one needs approx 40bhp to drive 70mph..)

Makes sense?

 

 

so... you can pootle around on idle, or give it beans. like an detroit v8, or an old-school diesel?

Glad to see they have used their initiative to reduce weight. This helps on so many fronts, not least handling (which audi sometimes needs help with when using huge engine blocks) and fuel range. Lets hope this and their recent success in making decent "fast cars" (RS4, R8) creates a new S4 that can compete with say the 335i and the C350.

Im sure i also heard that there is a Twin Turbo version of Audi's 3.0 V6 petrol motor in development too? Maybe LOATHER can help? Surely they wouldnt produce both! Id guess the Turbo version is much more likely.

I can confirm that my 335d coupe (twin turbocharged 3.0ltr diesel) gives 30mpg at 120mph cruising and 20mpg at 130mph cruising speeds.

I'm not entirely sure what use this is to the Audi S4 article except to say that my 335d will blow the next S4's socks off on a motorway and be more economical there or around town.

I think the point is even after copying/following BMW down the twin turbo 3.0ltr route they'll still be behind by about 2 years on the engine front!!   

Quattro369:

Im sure i also heard that there is a Twin Turbo version of Audi's 3.0 V6 petrol motor in development too?

You could be right, along the lines of VW's TSI supercharged and turbocharged 1.4 existing engine, although Audi would call theirs TFSI. Very little in German auto mags on this but a good article in American CarandDriver, see below:

http://www.caranddriver.com/reviews/hot_lists/car_shopping/latest_news_reviews/2010_audi_s4_to_get_supercharged_v6_updated_with_mileage_estimates_car_news

Onehp:

NiallOswald:

Why would they use a supercharger if they're looking to improve efficiency?

Because when you take it easy - supercharger hardly working, you have a "frugal" 3l V6

 

Yes, I understand the rationale behind using a smaller engine with forced induction over a larger NA engine. My question was really 'does the article mean turbine or belt-driven supercharger'. The problem with a belt-driven supercharger is a) The power to drive it is taken from the crankshaft and b) Its speed is determined solely by engine speed, meaning it's consuming power even when the engine is not being worked hard.

Given Audi's history of turbocharging, I would be surprised to see them using a belt-driven 'charger hence my question.
 

JJBoxster:

can confirm that my 335d coupe (twin turbocharged 3.0ltr diesel) gives 30mpg at 120mph cruising and 20mpg at 130mph cruising speeds.

 

interesting stats.  though is it really worth a 33% fall in economy to get an 8% increase in speed?

 

(yes i am an accountant!)

 

I would say alot of manufacturers will go the decrease in capacity route, it will be interesting to see if Audi can maintain/better the S4 perfomance.