[racprops]

Originally Posted by some_other_dave

How much do you know about the exact circumstances of the Shell mileage competitions? Those cars were completely optimized for "driving like an old man"--that's how they got such good mileage.

I even said so: a flying mile, at speed before they do any testing and I read it was at 30MPH.

OBD-II is not there to limit the fuel economy of modern cars. It is only an electric bus standard, in place so that a standard device can be plugged in and read diagnostic information about the vehicle.

Yes I know BUT with OBDII came a ton of sensors, most OBDI cars had only one O2 sensor OBDII have four, and the OBDI had chips that could be swapped, OBDII have to be flashed and you need special keys and codes to do so. It is night to day in changes, so yes the OBD interface IS a standard for readouts, BUT OBDII came with a lot of changes as well and is a marked point of that change.

If the manufacturers could simply tweak the intake system and get 20% better fuel economy, you'd better believe they'd do it in a heartbeat! They'd get much better CAFE credit (which would allow them to build more high-profit SUVs) and they could hit hard on advertising MPGs. There is no such tweak--at least, not that still passes emissions.

I don't buy that at all. Just as I don't buy that the car JUST happens to ware out certain parts, parts and service that keeps getting harder and harder to replace, and more and more costly to buy.


That's the closest to what you're talking about that actually exists: Lean burn. It isn't used any more because it produces high emissions, particular nitrides of oxygen. For a while, the emissions standards were lax enough that they could be passed while running lean burn (usually with some fancy and expensive catalysts), but standards have been tightened and LB can no longer meet them.

And I don't buy that either...there is too much money made by the oil companies, and the states in taxes on gas to allow any more than minor improvements in MPG..hear of the framer who converted all his machinery to Bio Diesel and lost the farm when the state came calling and wanted all the road taxes?



But that's not a problem with OBD-II, that's a problem with lean burn.

-soD

If they wanted to it could be done.