Does anyone have a fix to disable this feature?.The fix for the XJ is to remove the black cable from the small battery in the trunk.

 

You can try doing the same in the XF see if it works.

The good thing is BMW had enough complaints, so now the new models have the stop/start, but it has memory function. So, if you disable it, it will stay that way at every restart. Jaguar will hopefully do the same.

 

The XF 2.0T doesn't have it. The 5.0s don't have it. The 3.0 SC does.

It's not worth the fuel savings. The cranking on brake release is annoying and whatever minute fuel savings you get will not offset the drastically shortened life of the starter and not to mention accelerated engine wear. When you stop the engine oil flow stops. When you start the engine it takes a brief second or two to restore oil pressure and flow. Running your engine with oil starvation 20~30 times more often than you otherwise would sucks.

Turn it off and keep it off.