Cal. Veh. Code § 35559

(a)
1. (1) Notwithstanding any provision of this article, the power unit of a near-zero emission or zero-emission vehicle may exceed the allowable gross weight limits by up to a maximum of 2,000 pounds.
2. (2) The maximum allowance may apply to a single power unit or be distributed between more than one power unit, but shall not exceed a total of 2,000 pounds across a single vehicle or combination of vehicles.
3. (3) The maximum gross vehicle weight shall not exceed 82,000 pounds.
(b) This section shall not be construed to exempt any near-zero-emission or zero-emission vehicle from the weight limits prescribed in Article 2 (commencing with Section 35600), Article 3 (commencing with Section 35650), Article 4 (commencing with Section 35700), or Article 5 (commencing with Section 35750) of this chapter.
(c) This section shall not be construed to exempt any near-zero-emission or zero-emission vehicle from tire weight limits imposed by this code or in regulations adopted by the Department of the California Highway Patrol.
(d) For purposes of this section, “power unit” means a single unit or a combination of units in a near-zero emission or zero-emission vehicle that provide motive power to a drive system independent of any other power source.
(e) The terms “near-zero-emission vehicle” and “zero-emission vehicle” have the same meanings as defined in subdivisions (c) and (d) of Section 44258 of the Health and Safety Code.
(f) This section applies only to the extent expressly authorized by federal law.