This article is from the California Driving (and Surviving) FAQ, by "George J Wu" firstname.lastname@example.org with numerous contributions by others.
from email@example.com (Al Clark), firstname.lastname@example.org (Chuck Fry),
email@example.com (Dan Hepner), and firstname.lastname@example.org (David Levine)
in Jan 1993:
Assuming it meets Federal emission standards, you can register it in CA,
but you need to pay:
1) Use tax (in lieu of sales tax) for it's value, unless you did not buy it
for use in CA. If you owned the car for more than 90 days before you
brought it into CA, you are okay. The use tax is reduced by the amount
of sales tax paid to the another state, if owned for 90 days or less.
The stated purpose is to reduce any advantage one might have in buying a
car in some other state "for use in California".
2) Smog impact fee, a one time fee of $300. If the car meets CA emission
standards for the year of manufacture, this is not applicable. It says
what emission standards it was manufactured to meet on a sticker under
3) You'll need a smog check and certificate for most vehicles. Figure
around $40 for this.
4) Normal CA registration costs. Part of this is based on car's value.
This like a personal property tax, and this part is a deduction on your
Federal Income Tax.
For late model vehicles, the smog check is usually not a problem. First,
there isn't that much difference between "49-state" emission standards and
California's. Second, the smog checkers recognize that it's a 49-state car
and test it to the appropriate standard. Third, any well-maintained car
should have no problem passing even the stiffer California standards. A
modern catalytic converter-equipped car should be putting out air that's
almost as clean as it's taking in.
It's hard to generalize for older vehicles, such as those without catalytic
converters. The 49-state and CA emissions standards were quite different
way back when, and it's not unusual to be required to retrofit such items as
closed PCV systems and air pumps.
You don't have to bring a 49-state car up to CA tailpipe standards. The
stated purpose of the smog impact fee ($300) law is to fund checking up to
see if this was once a California car which was taken out of state and is
now being brought back in as a 49-state car not in compliance with CA's
standards. Many cars are "50-state cars", and have an emissions sticker
which claims that they meet the CA emissions standards, even if bought in
Maine. These cars are not subject to the $300 fee.
What you really do have to watch out for is removed smog control parts which
were perhaps legal, or quasi-legal to remove some places so long as the
emissions met local standards. In CA (and in many other states as well) the
smog test includes a visual equipment check: certain emissions-control
components must be installed and functional, regardless of the outcome of
the tailpipe test. This is because the tailpipe test is under very
restricted conditions (at idle and at one steady-state speed with no load)
and doesn't check all of the emissions species (just unburned hydrocarbons
and carbon monoxide). In contrast, the vehicle manufacturer had to
demonstrate compliance over a much more representative driving cycle, had to
meet standards for oxides of nitrogen and evaporative emissions, and had to
meet 50K or 100K mile durability requirements. More than one out-of-state
vehicle has met the recommendation "take it to Nevada and sell it" when the
cost of replacing such parts exceeded the value of the car.