Re: About mileage ?
I guess that would depend on the engine. The older engines that thay put emission controlling devices on would get better mileage with out them. But the new engines depend on these same devices to trim fuel for the best mileage/emissions possible for the load the engine is under.
Agreed.
Early emissions controls were band aids, regardless of brand.
Todays engines were/are designed with all that in mind.
Less fuel burned equals less emissions. It's simple physics.
There never was a 200 MPG carburetor and there never will be. Dang physics keeps getting in the way.
We're really seeing this today in diesels. Diesels are where gas engines were a decade or more ago. They're having to choke them down with EGR systems or God forbid, UREA injection (post combustion).
Not to mention, most of the #2 diesel you buy today is garbage. I've seen cetane ratings as low as 34. Most modern diesels need a minimum of 40 (some as high as 45) cetane to run with any efficiency. I recommend cetane boosters,
especially those offered by the OEM's. Your mileage WILL improve. More cetane=more effiecient burn=better MPG.
The days of letting your diesel idle are OVER. Most now have five minute shut downs incorporated in them. It is required in California.
It's actually a good idea. Nothing kills a diesel faster than letting it chug along at idle, for hours on end. Especially if it has a "particulate trap" and must "regenerate". You are gaining NOTHING. They don't burn enough fuel to generate any heat so what's the point? Other than it's "ingrained" in people heads.