Going into my fourth winter with this car 2007 xj8 , car starts good runs good, good gas mileage, problem is now we are into the sub zero weather i get a lot of white smoke[condensation] out of the tailpipe, this has been the normal since i have had the car, does not burn oil, or loose coolant, I do a 20mile school run most morning so engine is fully warmed up,, when i put the boot to it the white smoke is scary, even sitting in traffic it is visible ,, anyone any ideas? thanks in advance,
Dave
2007 xj8

 

It is water vapour from the combustion process that immediately goes to "cloud" when it hits the cold air. Nothing to worry about, I think, if everything else is going OK.

 

This is caused by the fact that burning a given volume of petrol produces five times that volume of water. In a cold climate this always remains visible unless you take the car for a long (50 mile plus) fast (120 mph plus) drive (naturally, I never do such a thing), to thoroughly warm the whole exhaust system. Even in temperate Southern England we suffer the same in Winter.

 

It is telling you the catalysts are warmed up and doing their job. The by-product of combustion through the catalytic converter is actually carbon dioxide, water vapor, and nitrogen gas and the heat of the cat will flash it off as steam. It's why stainless steel exhaust is used. What condenses in the pipe will come out as water droplets, and just like your breath in cold weather, what comes out the pipe will be steam.

 

Was thinking another way to see it is the harder you exhale, in the same temperature as the car, you produce a lot more vapors in the air don't you?

 

Thanks for the responses guys, I was thinking along the lines you mention, it just seems odd that all the other cars around including a few jaguars don't have as much coming out of their tailpipes, my nephew who works for Jaguar dealership as a tech tells me i fuss with the car too much, got to keep busy,
thanks again
Dave

 

Some oil does settle in the PCV and corrugated pipework.

Try finding a safe piece of road and kick it down a couple of times.

Don't worry if you get huge clouds of white/smoke.