CDTi's Purifilter(R) EGR Now Available for Sale to Fleet Operators

CDTi's Purifilter(R) EGR Now Available for Sale to Fleet Operators

Full EPA and CARB Verification Underway

VENTURA, Calif., Nov. 20, 2012 (GLOBE NEWSWIRE) -- Clean Diesel Technologies,
Inc. (Nasdaq:CDTI) ("CDTi"), a cleantech emissions control company, is pleased
to announce that the California Air Resources Board ("CARB") has issued an
Executive Order which allows CDTi to advertise, sell and install its
Purifilter® EGR diesel particulate filter ("DPF") pursuant to an exemption
while CDTi is waiting for a full and final verification from CARB.
Accordingly, CDTi is now taking orders for this breakthrough technology.

Due to its unique design, Purifilter® EGR, a passively-regenerating DPF,
provides exceptional filtration and regeneration efficiency for the removal of
particulate matter. The product addresses a significant number of exhaust gas
recirculation ("EGR") equipped heavy duty trucks currently subject to the
California Truck and Bus Regulation, which requires diesel trucks and buses
that operate in California to be upgraded to reduce emissions by various
deadlines.

With a full verification process currently underway by both CARB and the
Environmental Protection Agency ("EPA"), receipt of this Executive Order
enables CDTi to begin selling Purifilter® EGR to fleet operators while final
verification is pending. CDTi is offering the Purifilter® EGR under the CARB
After-Market Add-On Parts Exemption covered by the Executive Order. While not
currently approved under CARB's verification procedure and cannot be used for
compliance with CARB fleet rules, the Executive Order does permit CDTi to
advertise, sell and install Purifilter® EGR. In order to comply with CARB
fleet rules, CDTi must perform one of the following by the fleet owner's
specific compliance requirement date: Receive verification from CARB and
perform all necessary steps to ensure CARB fleet rule compliance; replace the
system with a verified system at CDTI's expense; or remove the installed
system and reimburse the full price of the system.

CDTi received the Executive Order from CARB on November 15, 2012.

"We are extremely pleased to have received the Executive Order from CARB,"
said Craig Breese, Chief Executive Officer of CDTi. "The verification process
has been lengthier than we had anticipated due to the unique and proprietary
nature of the product. However, we remain confident that full verification by
both CARB and the EPA will occur in the near future. We are delighted to add
Purifilter® EGR to our impressive portfolio of emission reduction systems, and
although the industry has experienced a slower than expected adoption rate
under the Truck and Bus Regulation, we are confident in our ability to win
business and continue our journey in leading the world in emission solutions."

Forward-Looking Statements Safe Harbor

Certain statements in this news release, such as statements regarding the
award of future verifications and the impact such verifications will have on
business, the future adoption rate of retrofit solutions and the future or
continued market acceptance of Company products constitute "forward-looking
statements" within the meaning of the Private Securities Litigation Reform Act
of 1995. Such forward-looking statements involve known or unknown risks,
including those detailed in CDTi's filings with the U.S. Securities and
Exchange Commission, uncertainties and other factors that may cause the actual
results, performance or achievements of CDTi to be materially different from
any future results, performance or achievements expressed or implied by such
forward-looking statements. Readers are cautioned not to place undue reliance
on these forward-looking statements, which speak only as of the date hereof.
CDTi assumes no obligation to update the forward-looking information contained
in this release.

The CDTi logo is available at
http://www.globenewswire.com/newsroom/prs/?pkgid=5742

CONTACT: Kristi Cushing, Investor Relations Manager
         Tel:  +1 (805) 639-9555

CDTi Logo