Car speed problem

Dear Sir, my friend recently purchased maruthi dezire diesel car. He felt the car is not exceeding the speed of 80km/hour as he travels a lot on highways because his business demands. He has to reach certain distances within the stipulation of time.(time is money) He felt after first service the speed issue will be alright. Nothing was changed. When technician was asked about this problem, he told that particular model's speed is limited to 80kmph. The car has not booked under taxi quota. Further detailed enquiry ECM kit which controls acceleration has to be changed if at all more than 80kmph is required. My contention is that why the automobile seller not felt responsible to inform about this nature of the particular model. And why should I pay 1lakh rupees replace the so called ECM kit for extra speed which I am looking for. Had they told earlier about this feature my friend might have choose another model which is fast enough to meet his requirements. Now he is driving a car which is not accelerating at certain places. Is my friend eligible to file case against the seller in consumer Court for selling a car which has speed limit and was not intimated to the buyer. And not going to do anything about it. Please explain Thank you Regards Khan.