Why some common car modifications are illegal!

Most car buyers think of modifying their cars at some point or the other either for individuality, functional or performance modifications. While some modifications are easy and simple, and are within the law, others are violations of the Central Motor Vehicle Rules 1989.

Why some common car modifications are illegal!

CarToq looks at some common modifications which are not really permitted under law, and if done, will either require RTO endorsement or are plain illegal, and can land you in a spot of trouble.


The normal specified dimensions of a car’s headlamp on the car should comply with IS 8415-1977 of the Bureau of Indian Standards. The rule 104 (3) of the Central Motor Vehicle rules states that all motor-vehicles can be fitted with two or four headlamps but that these should not positioned higher than 1.5 meters from the ground. The range a headlight should cover should be at least 155 metres. The rule 106 states that these lamps should be angled downward and should not blind anyone at a distance of more than 8 metres from the front of the light. Also read: How to modify your car’s suspension

The Automotive Industry Standards (AIS010 C8.2 / AIS037) state that for dual-filament H4 halogen headlamps, the maximum wattage for headlamps high-beam filament is 60 watts and the low-beam is 55 watts. Even with single filament bulbs, the maximum wattage specified in the AIS standards are 60 watts with a maximum of 1300 lumens of light emission. Most carmakers opt for 55/60 watt halogen headlamps, which is the international standard and/or 35 watt HID lights in their vehicles, in the interest of optimum power consumption, heat generation and longevity of the headlight reflectors, and staying within the prescribed standards. These lights, as long as they are focussed well, are complying with Rule 106 of the CMVR.

Fog lamps

Additional fog-lamps if fitted on a vehicle also need to comply with rule 104 and rule 106 of the CMVR. They cannot be fitted at a height of more than 1.5 metres from the ground. The beam pattern should also be one that does not dazzle. That means all roof-mounted fog lamps and additional lights are illegal. If you do have them installed on the roof, they have to be kept covered with a black cover at all times – and can be used only off-road and not on public roads. Also see: How to increase ground clearance

Rule 111 of the CMVR prohibits use of spot lights or search lights at the front of any vehicle except in exceptional circumstances, which requires the approval of the registering authority. So while normal fog lamps are permitted with maximum 55/60 watt power, high-powered search lights are not.

Exhaust pipes

Many owners think of fitting fancy exhaust systems on their cars to increase performance. When installing aftermarket exhausts, make sure the tail-pipe is to the rear or to the right of the vehicle, and not to the left of the vehicle – and it can have a maximum downward angle of 30 degrees. Exhaust pipes should also conform to noise level limits under Rule 120 of the CMVR, where it should not exceed 88 decibels of sound. So loud-sounding racing exhausts are illegal, unless they come under these noise limits. Related: Can you retrofit safety features in your car?

Fancy horns

You may have heard many taxis and other cars with fancy musical horns, especially on the highway. Well, these are illegal under Rule 119 (2) of the CMVR rules, where no vehicle is permitted to use a multi-tone horn that has a succession of different notes or any horn that is unduly harsh (exceeding 115 dB) . Only emergency and police vehicles are permitted to use multi-tone sirens.

Olive green colour

Many off-roaders love to paint their jeeps and off-road vehicles in olive green colour. This is not permitted under law, under Rule 121 of the motor vehicles act. This colour is only specifically permitted for the defence department, although you can work around this by not specifying “Olive” green, but any other green that is close to it.

Coloured indicator bulbs

Turn signal indicators have to be of amber colour only according to the motor vehicles rules (Rule 102). Amber colour lights should be fitted to the left and right of the vehicle, and should flash at the rate of not less than 60 flashes and not more than 120 flashes per minute. So vehicles, with red, blue or white turn signals are breaking the law. Also read: How to fix suspension problems

Changing body style

Chopping your SUV and making it into a pick-up truck may be cool or converting your sedan into a stationwagon may be practical, but these modifications are not legal. Your car’s body style is specified in your registration certificate and any change to the dimensions of the vehicle or to the body style will require it to be tested by the ARAI and given a fresh certificate, under Rule 126 where a prototype of every vehicle has to be approved. However, there are workarounds to this. For instance, modifying a Maruti Gypsy with a hard top from a soft-top does not change its dimensions (length and width), and so does not necessarily break the law.

Sun film

Sun film has been banned by the court citing reasons of rising crime by vehicles with dark tinted windows. So you can’t use sun-film of any kind on your windows now. And the glass used on your vehicle must conform to Rule 100 (2) of the CMVR, which states that the windscreen and rear glass should have at least 70% visible light transmission and side glasses should have at least 50% visible light transmission. Also read: 10 tools and spares to carry in your car



Fancy number plates

Number plates are supposed to be of a set style and standard. Any kind of fancy font or highly reflective material on the number plate is illegal. Under section 77 of the CMVR, a number plate must be of plain white color with a reflective surface for private vehicles on which the numbers should be in English and Arabic numerals with a font size of 6 cm high and 2 cm thick for letters and 9 cm high and 2 cm thick, with 1 cm gap between letters and border of the plate. Now the government has ordered high-security registration plates for all new cars, which anyway conform to these standards.

Share any other modifications you have seen on cars that you think don’t comply with the law. It’s good to keep the CarToq community aware of this.

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