[Vwdiesel] smoke related to driving style

[mikitka]

I was wondering does it make a difference on how you drive as to how much
smoke is produced out the tail pipe.  What I mean is, it seems that when I
drive my 91 TD Jetta easy to squeak out as much mileage per tank as possible
that when ever I do run the rpms up high and run it hard for the first time
after the easy driving it seems to put out serious smoke and then clears up.
So if I drive it hard again in a few miles down the road after that initial
smoke, it doesn't smoke half as bad.  So the harder I push the car the smoke
becomes less.  But if I drive it easy for a long time and then hit the fuel
pedal hard as in taking off from a stop light to jump ahead of traffic it
really smokes but then clears up.

 

Is it a carbon build up issue?  It only seems to do it when I drive it easy
and then push it hard.  Also, and I guess this is just normal for diesels,
but it will smoke more on a cold start for a few miles until it warms up.
That I take it is due to the efficiency of the engine isn't up to par until
it reaches normal operating temperature.

 

So far I have gotten 50mpg on two tanks and the third one was only 47.8.
That is because I really drove the car hard, some for fun, others for
running late to work and such and not running the normal 55mph but pushing
70mph for most of that tank. So 2.2mpg difference just for driving the Jetta
like I'm more use to driving isn't too bad of a deal if you ask me.  Also
the car is just reaching the 8k mark for mileage since I put the new rings
in so I'm hoping the mileage can come up a little more since it is still
new.

Nick