I disagree with Dinesh.Any kind of allowance is covered under the definition is taxable in terms of definition of Salary u/s 17 of the Income tax Act, 1961, except to the extent exempt u/s 10. In this regards, to the extent petrol allowance used in performance of ofiicial duties is exempt. See sec 10(14) with rule 2BB(1)(c). Also otherwise conveyance allowance for commuting between the office and residence is also exempt upto Rs. 1600 p.m in terms of section 10(14) read with rule 2BB(2). You can claim benefit in terms of said provisions.