2006 BMW Z4 3.0si Coupe - Specs

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VEHICLE TYPE: front-engine, rear-wheel-drive, 2-passenger, 3-door coupe
PRICE AS TESTED: $44,565 (base price: $40,795)
ENGINE TYPE: DOHC 24-valve inline-6, magnesium-and-aluminum block and aluminum head, port fuel injection
Displacement: 183 cu in, 2996cc
Power (SAE net): 255 bhp @ 6600 rpm
Torque (SAE net): 220 lb-ft @ 2750 rpm
TRANSMISSION: 6-speed manual
DIMENSIONS:
Wheelbase: 98.2 in Length: 161.1 in Width: 70.1 in Height: 49.9 in
Curb weight: 3080 lb
C/D TEST RESULTS:
Zero to 60 mph: 5.5 sec
Zero to 100 mph: 13.8 sec
Zero to 130 mph: 25.9 sec
Street start, 5-60 mph: 6.0 sec
Standing ¼-mile: 14.0 sec @ 101 mph
Top speed (drag limited): 156 mph
Braking, 70-0 mph: 154 ft
Roadholding, 300-ft-dia skidpad: 0.93 g
FUEL ECONOMY:
EPA fuel economy, city/highway: 20/30 mpg
C/D-observed fuel economy: 21 mpg


Does 40 hp really make that big of a difference?

Weight is the same and it has less torque!

Why 1 sec faster 0-60 that's a huge difference.

 

OK just figured one thing out.

The Z4's 2nd gear is tall enough that the car will surpass 60 with out a shift.

That still does not explain the big difference in 1/4 mile.

 

Power (SAE net): 255 bhp @ 6600 rpm
Torque (SAE net): 220 lb-ft @ 2750 rpm

This could be the reason ! By the estimated MPG, probably runnin bigger injectors !

Just my Dos Centavos

 

That is a good question.
It's a little lighter, but not even 200lbs.
I was going to say better gear ratios, but it's got a 3.07:1 so that's not it either.
Underated H.P.?

 

The car has roughly 20% more horsepower.

The numbers for the Z4 seem reasonable. But honestly the XF numbers seem a bit high. I've heard 14.7 for the 6MT base/limited XF. 0-60, in my opinion is closer to 6.2s than 6.5s.

I bet the Z4 has one fewer shift in the quarter mile than the Crossfire and that may make a big difference.

 

I think a big difference is the DOHC 24-valve inline-6 Engine.

It has 4 valves/cylinder compared to our 3 valves/cylinder... better flow of gas into and out of the engine. And I believe I6 engines produce more low end power easier... and the weight, even a couple hundred pounds does make a difference. It all adds up in the end, I suppose.

 

could it be harder launches? maybe its got a limited slip diff. i know i'll blow a tire loose easily even with my 275 rears. look at the 0-60 of 5.5 sec then look at the 5-60 street start of 6 sec. they are launching the car hard at take off. also at the track, i did have to go to 4th so another shift does loose time.

 

The numbers work out to roughly 14.5lbs/HP for the Crossfire but only 12lbs/HP for the Z4. That's fairly significant. Couple that to different ratios in the trans and rear end and you can make large gains in acceleration.

That's one way the new Nissan GT-R is so quick (besides Nissan understating the HP). A Z06 is still in 1st gear at 60mph while the GT-R has already reached 3rd. The Nissan is a LOT heavier than the Z06 but this gearing difference makes a huge difference. And, no, that's not the only reason for its performance, but it's a considerable part of it.

 

Good point Mike. In fact, if it weren't for the extra displacement and torque of the XF, the Z4 would be much faster.

I think overall the NA XF holds its own against its competitors. It makes up for its SOHC powerplant by using its larger displacement 3.2L engine. This gives it a bit more low end torque.

In the end, I'm glad that the XF uses a 3.2L engine. The tuning possibilities are really great for this car. The engine stands to produce upwards of 400+ WHP if built and tuned. If the boost pressure is brought up to 20psi or more, I imagine that tuners could put out 500+ WHP easily.

If the car shipped with something equivalent to the old supercharged merc 2.3L engine, this car would have been a total dead end. There really is no replacement for displacement!

 

Lighter rolling stock is also huge. Our cars come with 55 lbs hunks of metal in the rear, most performance cars are in the 30-35 lbs mark.

The 19" size is great for handling, but horrible for acceleration in such a low torque vehicle. Also, BMW ESP is much less intrusive and their ECUs don't pull timing as harshly as the Crossfire. The extra 40 HP and lighter weigt help as well. Less shifting and a smoother shifting trans add to it as well.

In Drag Racing it's not just the power to weight ratio that matters, some cars are set up better to put the power to the ground.

A better comparison would be from a roll with the TVT250 kit of course...

 

haha ok srt6dan

 

Come on now, at least this is performance related.

But really a better test would be at a roll, the Z4 will still pull, as it traps about 6 mph higher, but it won't be as bad.

 

haha i know im only messin with you