I reckon the EPA prefer to engines to be polluting instead of one properly tune and operating correctly. Nearly everything I get in to the repair shop is already beyond the EPA certification time so it doesn't matter I retune the engines to run correctly in the first place.
Yes a proper tuned pollutes less. Sometimes I think the rules are there just to force the customers into the major dealer shops.
I when I get though with an engine it usually gets better fuel economy than it did straight out the box as I do tune with a tach. I remember a little Dodge colt I drove at work that I tune to a point where the tail pipe was white grey and got 45 mpg. I even took my 265 V8 that was getting 16 mpg highway and when I got done with the mods it was cruising at 32 mpg highway with a combined mileage of 23 mpg and that was '79 model. MY current don't even 15 mpg combined with 4 speed overdrive automatic..
Well the EPA are Bureaucrats so they have to pass laws & regulations to appear to be doing their job and justify their pay checks
Now they could put emission limits on jet engines for instance , most of which dump around 200 gallons of raw jet A1 strait out the exhaust on take off.
But that would add $ 50 to the price of every air ticket and powerful politically connected people will not allow that to happen .
They could put obscuration meters on the stacks of trains & ships but again that will not be allowed by the megga wealthy
So making regulations so everything you buy has a very short life, requiring regular replacement thus making the megga rich even richer will go strait through parliament unopposed.
