One of my friends once told me that he would never get a diesel because it would do too much harm to the environment. A lengthy conversation was to follow his assertion.
Sounds to me that he is uninformed.
Off the top of my head response to your friend would go something like this:
Diesel is not a stiochimetic process that is to say air fuel ratio is varies from 23 to 1 full throttle to 100:1 at idle. Gasoline must be maintained a 15 to 1. So less fuel is burned per mile with a diesel.
Diesel has more stored energy than gasoline per gallon, again you go further per gallon.
Due to the two aforementioned scientific reasons diesels are obviously more efficient and thus you go significantly further on a gallon of diesel as compared to gasoline.
Diesel's longer stroke produce significantly more low end torque which is great for towing and acceleration. Do you think that 18 wheelers are slow off the line? Imagine how much slower they would be if they were gasoline not to mention how much more fuel they would burn!
Todays diesels are equipped with pollution control to appease you tree huggers, the NOx is reduced to N2 and H2O stuff humans have been breathing for tens of thousands of years. Diesels emit less Carbon monoxide than gasoline (about 50% less), Particulate matter filtered and is incinerated and no smell is now evident from the exhaust. The particulate matter is reduced to CO2 and H2O during the regeneration process.
As a personal opinion, I prefer the smell of non emission control diesel exhaust over that of a cold gas engine before the catalytic convertor is hot enough to be effective. In fact I find certain gasoline vehicles much more irritating to my nose and throat (vans seem to be the worst). With these new diesels I don't smell anything from a cold start.
for a laugh see this:
Guy gets yelled at by a fat Prius lady for having a diesel truck - YouTube
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