I test drove an 07 xk and it had fantastic acceleration from a stop, seemed very similar to the bmw 645 and Mercedes sl500 with quick pickup. I drove an 06 xk8 today and it's acceleration was very underwhelming, at least the first couple of seconds where you want that thrill. Is there something I don't understand?

 

The 2006 is several hundred pounds heavier than the 2007. That makes a big difference. Was one of them a convertible and the other a coupe? The convertible requires extra stiffening, which makes it even heavier. The engines are the same, but the 2007 engine was tweaked a little and it puts out 300 HP compared to 294 HP of the 2006.

The little things can add up. Plus the 2006 might have issues that are preventing it from developing full power.

 

They were both convertible. I guess I should drive more than one to make a good comparison.

 

As Sam said one is heavier being the xk100 and the other a few hundred pounds lighter it does make a big difference

 

Plus, the looseness of the X100 can add to the 'sloth' feeling of slowness while not being quite as slow as it seems to be.

 

There is also a throttle cable issue in the X100 that over time doesn't let the throttle actually depress fully. It's an easy fix but many X100 owners complained of reduced power before tightening. However, the X100 at speed on curves is just plain scary.

 

Yes! I forgot about that! I think I actually made a video of how to fix it. The throttle cable stretches over time, but there's an adjustment at the throttle that lets you take out the slack.

 

 

I think the electronic throttle has a lot to do with it as well. The throttle plate opening doe not create a linear airflow increase so the electronic version opens it more at lower throttle pedal positions. Ford installed a trapeze linkage on the '60's car's throttle rods to do the same thing.

 

The 2007 (X150 )is built of aluminium and the 2006 (X100) is steel.
I believe the 0-60 time for the standard 2007 XK is similar to the 0-60 time for the 2006 XKR.

 

Also VVT was added in 2007.

 

Didn't the n/a already have vvt