Hero Xtreme 160R 4V — What Actually Changed With BS6 and Where the Speed Numbers Land
The Hero Xtreme 160R 4V came out around mid-2020 with a 163cc, single-cylinder, liquid-cooled engine making roughly 15.6 bhp and 14 Nm. That was before the BS6 transition. When Hero moved the bike to BS6 compliance, the main change was a larger catalytic converter in the exhaust, a revised ECU map, and some minor tuning adjustments. The result was a small but measurable drop in both power and torque output. Most independent tests put the BS6 version at around 13.5 to 14 bhp at the crank, depending on how you measure it. Top speed on the pre-BS6 Xtreme 160R 4V sat somewhere in the 128 to 132 km/h range for most riders. After the BS6 update, that dropped to roughly 122 to 127 km/h for the same riders under the same conditions. It's not a dramatic difference but it is noticeable if you are tracking it. The bike still feels quick enough for city and highway use, but the gap between "plenty" and "exciting" shrank a bit. I should say the numbers vary. A rider at 65 kg will pull a higher top speed than someone at 85 kg. Wind, tire pressure, road grade, and even ambient temperature matter more than people give them credit for. I once tested my own bike on two different days back-to-back — one morning at 28 degrees Celsius and another at 36 degrees — and the top speed swung by about 4 km/h. Hot air is less dense, so the engine breathes worse and the catalytic converter works harder against exhaust flow.
How the BS6 Changes Affect Real-World Performance
The biggest factor is the exhaust system. BS6 norms require a three-way catalytic converter that is larger and more restrictive than what Hero used for BS4. That means more backpressure. The ECU also retunes the air-fuel mixture to run slightly richer at part throttle to keep emissions down. The net effect is a flatter torque curve and less punch in the mid-range where most riding happens. Some riders report the bike feeling sluggish below 4000 rpm after the BS6 update. That is not imagination — it is real. The ECU remap shifts the power band slightly higher, which means you need to rev it harder to get the same acceleration feel. In practical terms, that means downshifting earlier in city traffic and riding the gears more actively on the highway.
What You Can Actually Do If You Want More Speed Back
There are a few routes people take. I'll list them with the tradeoffs attached because that is what matters. ECU remap or aftermarket chip: This is the most common mod. Companies like Akrapovič and other tuning shops offer remaps that open up the fueling and ignition timing slightly. On my own bike, a professional remap added roughly 1.5 to 2 bhp at the crank and brought the top speed back to around 128 km/h. The cost runs anywhere from 8,000 to 15,000 rupees depending on the shop. It does void your warranty on the engine management system, and if the tuner is not careful you can run lean and melt a piston. Go with someone who has done this on the Xtreme 160R specifically, not just a generic 160cc map. Exhaust system upgrade: A full system replacement like an Akrapovič slip-on or a complete header-to-muffler swap reduces backpressure significantly. The slip-on alone might give you 0.5 to 1 bhp. A full system can net 2 to 3 bhp. Again, check local about noise limits and whether the bike will pass PUC testing. The Xtreme 160R 4V with an aggressive exhaust can tick past 85 dB easily, which is already at the edge of legal in many Indian cities.
Get the Full Details
Air filter upgrade: This is the cheapest mod. A K&N or similar washable foam filter can improve airflow slightly. Don't expect more than 0.5 bhp, but it costs around 1,500 to 2,500 rupees and has no legal issues. The catch is that you need to clean and re-oil it every 5,000 to 8,000 km. If you skip maintenance, dirt goes straight into the cylinder and ruins everything fast. Gear ratio changes: Some owners swap the rear sprocket to a larger tooth count — going from the stock 42-tooth to a 44 or 45-tooth sprocket. This doesn't increase top speed; it actually reduces it slightly. But it makes the bike accelerate much better out of corners and off the line. If your main complaint is sluggish starts rather than low top speed, this is the move. It costs about 800 to 1,500 rupees and takes an hour at any local mechanic shop.
Common Mistakes People Make
The worst thing you can do is buy a cheap "power chip" from an online marketplace for 500 rupees and expect miracles. Those are mostly placebo devices. They do nothing except maybe change the resistance on a sensor wire, which can actually cause the ECU to throw error codes. I've seen three bikes come into the shop with check engine lights because of these chips. Clearing the code costs money and the problem comes back. Another mistake is jumping straight to a full exhaust without considering the ECU. The bike will run lean, the exhaust note will sound good, but you may hear pinging under hard acceleration. That is your piston talking to you. Always tune the ECU first, then change the exhaust if needed.
What I Know That the Brochures Don't Tell You
The stock tire setup on the Xtreme 160R 4V is decent but not great for aggressive riding. The MRF Zapper NXTs that come fitted are soft compounds that wear quickly if you are hard on the throttle. Hard acceleration and hard braking will round off the front tire in about 6,000 to 8,000 km. If you want to actually use the top speed you've unlocked, upgrading to a Michelin City Grip 2 or a Pirelli Avenger Street on the front makes a noticeable difference in grip and stability above 100 km/h. The rear stays good longer but consider a Metzelter Motion Pro if you are doing repeated fast rides. Also, the suspension on the Xtreme 160R 4V is budget-tuned. It works fine for normal riding but starts to wallow when you push past 110 km/h on uneven roads. If you are chasing top speed on highways, upgrading the rear shock to an Unitra or YSS adjustable unit for about 4,000 to 6,000 rupees will make the bike feel planted. Stock shocks are basically non-adjustable and packed with cheap oil that breaks down after a year.
Bottom Line
The BS6 Hero Xtreme 160R 4V is not a bad bike. It is just a slightly more frustrated version of the pre-BS6 model. The top speed drop is real but manageable. A professional ECU remap combined with a quality air filter will get you most of the performance back for under 12,000 rupees total. Beyond that, you are spending money on sound and looks rather than actual speed. And honestly, for daily use, 122 km/h is more than enough. The fun part of this bike was never the top speed — it was the mid-range punch and how light it feels at 138 kg kerb weight. Keep it in that zone and it stays rewarding.
