ESFO

100lbs +/- more than an S4? When you consider the weight reduction measures built into the vehicle it really makes it strange.

dxben

Just a wild seres of guesses...

Engine weighs more?

The larger rotors/brakes?

Does the Dynamic Ride Control add weight?

19" Wheels weigh more?

Wider track adds more surface area for some panels?

Parikh1234

what exactely makes this car 300 lbs heavier than the euro version and how much safer do those components make the car?

Redfoot

I recently weighed my car and got 4120 lbs.
Thats was with me, my 17" winter wheels, spare tire, 1/2 tank of fuel, 2 child car seats, and a crap load of other stuff. Left my golf clubs at home on this particular day.

As ESFO goes for the record of the lightest B6S4, I'm trying for the heaviest.

Bob W.

I think if you compared the RS4 with a *loaded* B7 S4, the weight would be the same. DRC plus the extra standard equipment, and bigger wheels and tires, probably adds up to 100 lbs. The published weight for the S4 is for a base model (i.e. no sunroof, etc.).

More importantly, the published performance numbers we're seeing for the US spec car are no different from the Euro spec, which is supposedly 200 lbs lighter.

The aluminum hood and fenders could be seen as more of a weight redistribution move.

Bob W.

I think the MT car had rear airbags, which add some weight. Base S4 has no sunroof.

dxben

Is there an echo in here?

ESFO

(This is a reply to this and dxben's post...)

It's not as if DRC adds more shock absorbers. It simply connects the diagonally opposed absorbers hydraulicly.

Bigger brakes don't necessarily mean more weight. Look at all the aftermarket big brake systems, most notably the ECS Tuning Stage 4 kit which uses the Porsche Cayenne 6 piston calipers. Those larger calipers weigh 5 pounds less than the S4's stock, smaller calipers.

Whether the engine weighs more is actually a good question. While the block and heads are the same material as the S4's, the crankshaft is "new". It may weigh a little more. I suspect it would need to be stronger to sustain 8250 rpms. The connecting rods and pistons may actually be lighter tho'.

The 18" Avus+tire weigh in at just over 50lbs per, about the same as the 19" RS4 wheel+tire. Consider the sheer mass of the 18" Avus...

And the aluminum panels should well offset any negligible weight increase due to marginal increases in surface area.

Note too that the RS4 has no spare tire and the S4 does which offsets the weight added for the standard sunroof in the RS4.

I would suspect that there's more chassis bracing to increase structural rigidity.

It seems the mystery lingers on. It would be nice if the corporate Audi folks who sometimes peek at the forum would anonymously chime in sometimes to elucidate when questions like this come up.

Bob W.

it's got to be more than a couple of pounds...the owners manual weighs a couple of pounds!

regarding the wheels & tires, remember the tires are bigger in the RS4 also...probably a couple pounds/tire at least. I don't know if anyone has weighed a 19" RS4 wheel and tire together....I haven't seen it posted, but I'd be surprised if it was the same as the S4 Avus wheel+tire.

and regarding the brakes....most of the weight is in the rotors, not the calipers. and the rotors are substantially larger, though they do have aluminum hats.

I think the engine probably weighs a little less in the RS4. It holds almost 3 qts less oil, for one thing. Plus there are 8 fewer valves in the RS4 V8 than the S4 V8.

Fuel tank is slightly larger in the RS4...0.3 gallons bigger.

ESFO

The hydraulic lines don't weigh much at all. I don't even know if you'd get up to two pounds in lines and fittings considering their diameter. How much hydraulic fluid? Dunno. Not a lot. You don't need a large reserve tank or anything. The brakes probably weigh less just like the aforementioned ECS Stage 4, both of them using larger rotors and calipers. Looking at the weight of the 18" RS4 wheel which weighs about 3 pounds less than the Avus, I figure the wheels are a wash between 18"Avus and 19"RS4. But, yes, the tires weigh about 2 pounds more each. The engine is a mystery because we don't know crankshaft material in either engine. Weight from 8 valves is minuscule.

Again, it's a mystery. We're looking for 100lbs, not 20. I'm sure the answer will become clear in time. We're on the steep part of the learning curve with this car. As people begin to modify and lighten we'll really learn some things.