I would like to double my gas mileage to comply with the new standards-how do I do this?

What new government standards are you talking about? You can't double your gas mileage unless you want to pay a huge amount to convert your car. It is so expensive to do that it isn't worth it unless you're driving 100,000 miles a year.

Short of putting in a "New, standard" engine, I don't know. Maybe a motor 1/2 the displacement? Put in a 5-speed?

Only by common sense can you practically improve mileage; I think 33% is tops. This is by tuneups. Platinum plugs, synthetic oil, radial tires that are taller than stock and keeping them inflated, wheel alignment, and a smaller alternator.

Accelerate slowly; take foot off gas downhill. Keep windows rolled up on freeway and use A/C at lowest setting you can stand. Combine trips to prevent stop-start and short trips. Get an early startt/late return to avoid traffic jams.

Just common sense things.

The new standards don't come into effect until 2025.

Do you plan to be driving your present car 14 years from now?

I believe those standards were put in place for automotive manufacturers. I could be wrong...