Why is the ZT 190 so slow on paper?

[Ahrle]

Hello forum,

My first thread here.

Just got a ZT-T 190, lovely car! Just wonder how it spec-wise could be so slow. My previous car, an E39 BMW 525i Touring, is 160kg heavier, has no more power, and is certainly quicker according to (saloon) specs

From Zeperfs:

ZT 190/525i E39:

Motor: 2.5 V6 24V | 2.5 I6 24V
Power: 190hp @ 6500 | 192hp @ 6000
Torque: 245Nm @ 4000 | 245Nm @ 3500
0-100 claimed: 8.2s | 8.1s (Touring 8.5s)
0-100 verified: 8.8s | 8.0s
0-180 verified: 32.6s | 26.5s
Top speed claimed: 225 | 238 kph (Touring 235 kph)
Top speed verified: 224 | 231 kph
Verified weight*: 1520/1680 kg

*My 2003 ZT-T 190 and 2002 525i Touring, full tank, 65 kg driver

So the E39 Touring is 160kg/350lbs heavier, and according to specs, quicker (Touring can't weigh 180 kg more if 0-100 is just 0.4 seconds slower).

Another example is 325Ci E46 (Zeperfs), also quicker, being a passenger heavier than the ZT.

I'm curious about this mystery. Given the huge weight difference to the charts, have someone done a Racelogic test or dyno'd a stock 190? What were your results?

Thank you,
Ahrle