I've learnt a fair deal on this thread, and I'm indebted to your views, Scott.
The black smoke has several causes, and one of which is traces of water mixed with fuel. I agree, in our hot and humid condition, vapour forms in the huge diesel tank - and we have to drain this little bit of water out (water being heavier than diesel will naturally lie at the bottom). This is normally done in the morning when it settles well.
Indeed many of the buses on our Malaysian roads do not practice this simple method of draining, thus causing unwarratned damage to the emgine, and increased emission of black smoke. The service technicians from HINO has repeated reminded us to perform this simple procedure.
Our drivers are trained to drive in the most professional manner - and the screening process is thorough as we do not wish to employ drivers who are incompetent. So much so, we have allocated an extra monthly incentive for upkeep of buses, which includes the way they drive, i.e. 1 complain and the incentive is deducted. So how, its a clean record for all our drivers.
Condensation is unavoidable. If its minor than it's burned up in the combustion process. But its not from what we have experienced. We get to extract approximately 10 ml fortnightly, +/- 10%.
Upon extraction, the waste are all deposited into a canister that will be taken by the oil company servicing our depot. So, we don't add any more pollution into the environment than there already is.
I am vey particular about this as I believe we shouldn't be doing things in the short term.
Its a Saturday, and wishing you'll a happy and safe weekend.
[Edited by ymsin on 03-31-2001 at 05:08 AM]