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Join Date: Feb 2004 Location: Bombay Posts: 23,178 Thanked: 28,603 Times

Driving the e2o



Let's get this out of the way first. After seeing how the e2o is a full-featured hatchback alternative when it comes to the interiors, the next logical question is : Can the e2o keep up with traffic on the average intra-city commute? I think the answer is YES.



Acceleration & Driveability



The e2o is powered by a 19 kW (kilo-watt) electric motor. That translates to about 25.5 BHP @ 3,750 rpm. It might sound measly (even the 2-cylinder Nano has 37 BHP), but the numbers don't really tell the true story in terms of driveability, as we're only looking at the peak output. Also, keep in mind that unlike internal combustion engines which start off weak at low rpms and then build up their power/torque output as the revs climb, electric motors have a perfectly flat torque curve all through their range. Translated, 100% of the e2o's 53 Nm of torque is available right at 0 rpm, all the way up till 3,400 rpm. The Nano in comparison would only attain its peak torque of 51 Nm @ 4,000 rpm. Most Nano drivers have probably never revved till 4,000 rpm!



Naturally this flat torque curve of electric motors is great for starting off, as well as slow-speed driveability. The instant response you get from a standstill lets the little e2o shoot ahead of all other casually driven cars in the traffic-ridden stop light Olympics. No need to engage any gears, no need to slip the clutch and no need to wait till your motor or turbo revs up enough. There's no lag, and the acceleration is smooth and jerk-free. It's lovely to dart through gaps in slow moving traffic. The car's size helps too. A simple dab of the accelerator and the e2o effortlessly zips off without making a big hue and cry about it. The e2o really shines in these typical stop-and-go traffic conditions (especially since there's no clutch), making it an absolute pleasure to drive in the city.



However, if you're besides an aggressive driver, or the road ahead opens up and the speeds continue to increase, that’s when the internal combustion cars will shoot past the e2o quite easily. If the highway is part of your daily commute, the e2o will leave you underwhelmed. You'll need to be a fairly patient person.



Once you cross 60 km/h, progress gets slower and throttle response is fairly dead. I managed to get the car up to 83 km/h on its own steam, and 90 km/h on a downhill stretch. It touched top speed without a big hue and cry. Unlike internal combustion engine'd cars, the e2o doesn't scream and strain as it reaches the end of its capabilities. It's much less obvious that it's being pushed to the limit. The rate of acceleration just slows down, until you're zipping along at a constant speed, even if you keep your foot down. A soft electric whine will give you company. Despite the slower progress as speeds increase, it's not at all uncommon to find yourself in the 70s at most open stretches during your daily commute.



Click the gear lever back one position, and you're in "B"oost mode. This driving mode lets the motor have more juice, and the e2o gets noticeably peppier. I'd say it feels like a 15% increase in power. 0-60 km/h takes 11.5 seconds in boost mode. Boost was probably not worked into the standard mode since it uses up more of the battery, and generates more heat & strain for the motor and battery pack. Quite frankly, the car does pretty well in most situations without it. In boost mode, you'll be at 80 km/h in the same time it would normally take you to get to 60 km/h. There is no limit to how much you can use the boost mode, though once the battery level drops below 20%, it gets deactivated to save charge. Aside from tickling the fancy of zippy drivers, the boost function is extremely useful when you want a little extra push going uphill.



Remember the flat torque curve of the electric motor? That makes hill climbing a steady affair. The car will chug uphill at a constant (and respectable) speed. Switch to boost mode, and it will begin to accelerate. I attacked some steep hills in South Mumbai (Manav Mandir & other Malabar Hill ascents) and the e2o climbed `em without a fuss in regular drive mode. Not a honk was heard behind me.



It feels good to be stuck in traffic with the A/C on. The guilt of running just the AC on fossil fuels isn't present with the e2o. There's no heat emanating from the car, and no fumes either. I dream of being stuck in an all-electric traffic jam. It would be the peaceful future.



It's worth mentioning that the car does not start moving when you lift your foot off the brake (like a conventional AT). It requires accelerator input. Another point is that, regardless of which gear you're in, the car will roll just like it's in neutral, unless you are pressing the accelerator or have the brakes engaged. Nervous drivers, don't fret - it does have a hill-hold function that keeps the e2o in place for 1 second after you release the brake pedal, and then lets it roll backwards very slowly after that.



There is a mild electric whine when you're accelerating. It gets softer when you take your foot off the accelerator. I got used to it pretty quickly, and started to enjoy it a bit too. At a standstill, there is an electric-fan like whine that seems to be coming from the dashboard or foot-well area. It's usually the cooling fans for the battery pack and motor below the car. There's another electric whirring sound when you press the brakes. You might notice these sounds and find them louder than expected, but the reality is that you're only noticing them more because the noise of an internal combustion engine idling away is not muffling them out.



Watch this quick video to see it in action

http://www.youtube.com/watch?v=Cp8tGJecdG4



Ride & Handling



The e2o does not have a power assisted steering. Chances are it's more about cost saving than it is about the extra drain that an Electric Power Steering (EPS) would put on the battery. Because of this, when the car is not in motion, the steering is extremely heavy. You'll need to use two hands at 0 km/h. Get the car moving slightly and it gets better, but even when the car is in motion, it's still on the heavier side of things. It's nowhere near the light EPS units of other hatchbacks. Due to the suspension geometry, the steering is also not very keen to return to center after you complete a turn.



The turning radius at just 3.9 meters is ridiculously small on paper. However, in reality it's not as impressive as you'd expect. Due to the lack of power steering, it takes you a while to turn the wheel all the way. If you do wind up the steering completely in preparation, making a U-turn on a single-lane road is well within the capabilities of the e2o.



The e2o is a rather neutral handler. The 155 width tyres are okay for a car of this size and weight. There's no understeer, but there is a fair amount of body roll. If you take corners quickly, or change lanes suddenly, it's apparent. Naturally so, because this is a fairly tall car with an extremely narrow stance. At high speeds (70+ in this case), it can take corners quite confidently (eg. the serpentine Muhammad Ali bridge in Mumbai). However, the e20 requires a good road to do this. If the surface has bumps and ruts, the e2o will dance around on turns and it's not very confidence inspiring.



The suspension was a mixed bag on our test car. It sounded like parts were loose on multiple occasions and felt rather toy-like at times. There was some plasticy squeaking emanating from the left of the dashboard too. The ride is acceptable at the front and thanks to the tall-boy seating position, the overall level of comfort is good. You do tend to feel smaller discrepancies on the road surface though.



When I was alone in the car, the rear wheels would jump off speed breakers with a loud thud, like they were attempting suicide - even at slow speeds. It's like the rear suspension didn't have the ability to soak up bumps when the rear seats are vacant.



I was really not looking forward to my turn as a rear passenger - for fear of another herniated disc. However, once I was back there, I didn't have any complaints. We did the same route I had done alone, and things were well within acceptable limits. It turns out that putting a little weight on the rear axle takes care of the jumpy rear end.



Other than the consistent electric hum, there's no audible tyre noise inside the cabin. Perhaps the low rolling resistance tyre tread design and the narrow 155 mm contact patch are to thank for this. There's no wind noise heard inside the cabin either, probably due to the not-very-high top speed of 83 km/h.



Ground clearance at a high 180 mm was never an issue during our 200+ kms of driving the e2o.



Braking



In one sentence, the braking capability is good, but the brakes have an unpredictable and sudden bite to them.



Let me explain that further. When gradually depressing the brake pedal, the e2o begins to slow down. However, at some unpredictable point in this deceleration, the brake force suddenly quadruples. This forces the driver to release the pedal a bit to accommodate. It brings up the constant fear of being rear-ended, and there's really no getting used to the erratic braking behaviour. Mahindra needs to fix this problem.



Why is this happening? Was it something to do with the regenerative braking? Doesn't make sense as the regenerative braking kicks in very seamlessly as soon as you take your foot off the accelerator (you don't even need to press the brake pedal). At least that’s what the "E gen" indicator on the dash seems to indicate. It feels just like coasting in 3rd gear in any other car. Could it be activating more aggressively when the brake pedal is pressed? Nah.



The e2o has disc brakes at the front, and there is a vacuum-assisted brake booster present. These are "Power Brakes" - just like every other car on the market. But wait, those systems use the vacuum generated by the internal combustion engine to operate the booster. How does the electric e2o do it? Turns out, this was the problem. There was a small motorized vacuum generator that would spin up every time it felt there wasn't enough vacuum available. This resulted in a huge and sudden power-assist to the booster, which caused the unpredictable braking behavior. How can we be sure? Well, I unplugged the electric vacuum generator and it fixed the problem (Obviously not a solution, since the brake pedal becomes extremely hard to press without the vacuum assist).



Adding to the regenerative braking point, it appears that the 'E gen' disengages at 1-2 km/h, just before the car is about to come to a stop. This means you have to press the brake pedal just a wee bit more to compensate and bring the e2o to a dead stop where you expected it to. This is noticeable in traffic as you slow down and plan to stop close behind another car.



Due to the short wheelbase and track, braking hard while taking extremely sharp corners can cause one of the rear tyres to lock up and skid a little. I was enthusiastically pushing along my twisty home-stretch when I experienced this a few times, though I really doubt that the average e2o owner would face a similar situation more than once or twice in their entire ownership.







A strip of velcro holds the spare tyre in place. It's extremely easy to access and lift. The jack is mounted with a wing-nut. They are both secured very firmly:





Differential on the rear axle (in foreground) with the motor in the background. What's between them is all there is of the transmission:





The electric vacuum pump (silver) is connected to the brake booster. When this turns on, it makes the brakes bite suddenly:

Let's get this out of the way first. After seeing how the e2o is a full-featured hatchback alternative when it comes to the interiors, the next logical question is : Can the e2o keep up with traffic on the average intra-city commute? I think the answer isThe e2o is powered by a 19 kW (kilo-watt) electric motor. That translates to about 25.5 BHP @ 3,750 rpm. It might sound measly (even the 2-cylinder Nano has 37 BHP), but the numbers don't really tell the true story in terms of driveability, as we're only looking at theoutput. Also, keep in mind that unlike internal combustion engines which start off weak at low rpms and then build up their power/torque output as the revs climb, electric motors have a perfectly flat torque curve all through their range. Translated, 100% of the e2o's 53 Nm of torque is available right at 0 rpm, all the way up till 3,400 rpm. The Nano in comparison would only attain its peak torque of 51 Nm @ 4,000 rpm. Most Nano drivers have probably never revved till 4,000 rpm!Naturally this flat torque curve of electric motors is great for starting off, as well as slow-speed driveability. The instant response you get from a standstill lets the little e2o shoot ahead of all other casually driven cars in the traffic-ridden stop light Olympics. No need to engage any gears, no need to slip the clutch and no need to wait till your motor or turbo revs up enough. There's no lag, and the acceleration is smooth and jerk-free. It's lovely to dart through gaps in slow moving traffic. The car's size helps too. A simple dab of the accelerator and the e2o effortlessly zips off without making a big hue and cry about it. The e2o really shines in these typical stop-and-go traffic conditions (especially since there's no clutch), making it an absolute pleasure to drive in the city.However, if you're besides an aggressive driver, or the road ahead opens up and the speeds continue to increase, that’s when the internal combustion cars will shoot past the e2o quite easily. If the highway is part of your daily commute, the e2o will leave you underwhelmed. You'll need to be a fairly patient person.Once you cross 60 km/h, progress gets slower and throttle response is fairly dead. I managed to get the car up to 83 km/h on its own steam, and 90 km/h on a downhill stretch. It touched top speed without a big hue and cry. Unlike internal combustion engine'd cars, the e2o doesn't scream and strain as it reaches the end of its capabilities. It's much less obvious that it's being pushed to the limit. The rate of acceleration just slows down, until you're zipping along at a constant speed, even if you keep your foot down. A soft electric whine will give you company. Despite the slower progress as speeds increase, it's not at all uncommon to find yourself in the 70s at most open stretches during your daily commute.Click the gear lever back one position, and you're in "B"oost mode. This driving mode lets the motor have more juice, and the e2o gets noticeably peppier. I'd say it feels like a 15% increase in power. 0-60 km/h takes 11.5 seconds in boost mode. Boost was probably not worked into the standard mode since it uses up more of the battery, and generates more heat & strain for the motor and battery pack. Quite frankly, the car does pretty well in most situations without it. In boost mode, you'll be at 80 km/h in the same time it would normally take you to get to 60 km/h. There is no limit to how much you can use the boost mode, though once the battery level drops below 20%, it gets deactivated to save charge. Aside from tickling the fancy of zippy drivers, the boost function is extremely useful when you want a little extra push going uphill.Remember the flat torque curve of the electric motor? That makes hill climbing a steady affair. The car will chug uphill at a constant (and respectable) speed. Switch to boost mode, and it will begin to accelerate. I attacked some steep hills in South Mumbai (Manav Mandir & other Malabar Hill ascents) and the e2o climbed `em without a fuss in regular drive mode. Not a honk was heard behind me.It feels good to be stuck in traffic with the A/C on. The guilt of running just the AC on fossil fuels isn't present with the e2o. There's no heat emanating from the car, and no fumes either. I dream of being stuck in an all-electric traffic jam. It would be the peaceful future.It's worth mentioning that the car does not start moving when you lift your foot off the brake (like a conventional AT). It requires accelerator input. Another point is that, regardless of which gear you're in, the car will roll just like it's in neutral, unless you are pressing the accelerator or have the brakes engaged. Nervous drivers, don't fret - it does have a hill-hold function that keeps the e2o in place for 1 second after you release the brake pedal, and then lets it roll backwards very slowly after that.There is a mild electric whine when you're accelerating. It gets softer when you take your foot off the accelerator. I got used to it pretty quickly, and started to enjoy it a bit too. At a standstill, there is an electric-fan like whine that seems to be coming from the dashboard or foot-well area. It's usually the cooling fans for the battery pack and motor below the car. There's another electric whirring sound when you press the brakes. You might notice these sounds and find them louder than expected, but the reality is that you're only noticing them more because the noise of an internal combustion engine idling away is not muffling them out.The e2o does not have a power assisted steering. Chances are it's more about cost saving than it is about the extra drain that an Electric Power Steering (EPS) would put on the battery. Because of this, when the car is not in motion, the steering is extremely heavy. You'll need to use two hands at 0 km/h. Get the car moving slightly and it gets better, but even when the car is in motion, it's still on the heavier side of things. It's nowhere near the light EPS units of other hatchbacks. Due to the suspension geometry, the steering is also not very keen to return to center after you complete a turn.The turning radius at just 3.9 meters is ridiculously small on paper. However, in reality it's not as impressive as you'd expect. Due to the lack of power steering, it takes you a while to turn the wheel all the way. If you do wind up the steering completely in preparation, making a U-turn on a single-lane road is well within the capabilities of the e2o.The e2o is a rather neutral handler. The 155 width tyres are okay for a car of this size and weight. There's no understeer, but there is a fair amount of body roll. If you take corners quickly, or change lanes suddenly, it's apparent. Naturally so, because this is a fairly tall car with an extremely narrow stance. At high speeds (70+ in this case), it can take corners quite confidently (eg. the serpentine Muhammad Ali bridge in Mumbai). However, the e20 requires a good road to do this. If the surface has bumps and ruts, the e2o will dance around on turns and it's not very confidence inspiring.The suspension was a mixed bag on our test car. It sounded like parts were loose on multiple occasions and felt rather toy-like at times. There was some plasticy squeaking emanating from the left of the dashboard too. The ride is acceptable at the front and thanks to the tall-boy seating position, the overall level of comfort is good. You do tend to feel smaller discrepancies on the road surface though.When I was alone in the car, the rear wheels would jump off speed breakers with a loud thud, like they were attempting suicide - even at slow speeds. It's like the rear suspension didn't have the ability to soak up bumps when the rear seats are vacant.I was really not looking forward to my turn as a rear passenger - for fear of another herniated disc. However, once I was back there, I didn't have any complaints. We did the same route I had done alone, and things were well within acceptable limits. It turns out that putting a little weight on the rear axle takes care of the jumpy rear end.Other than the consistent electric hum, there's no audible tyre noise inside the cabin. Perhaps the low rolling resistance tyre tread design and the narrow 155 mm contact patch are to thank for this. There's no wind noise heard inside the cabin either, probably due to the not-very-high top speed of 83 km/h.Ground clearance at a high 180 mm was never an issue during our 200+ kms of driving the e2o.In one sentence, the braking capability is good, but the brakes have an unpredictable and sudden bite to them.Let me explain that further. When gradually depressing the brake pedal, the e2o begins to slow down. However, at some unpredictable point in this deceleration, the brake force suddenly quadruples. This forces the driver to release the pedal a bit to accommodate. It brings up the constant fear of being rear-ended, and there's really no getting used to the erratic braking behaviour. Mahindra needs to fix this problem.Why is this happening? Was it something to do with the regenerative braking? Doesn't make sense as the regenerative braking kicks in very seamlessly as soon as you take your foot off the accelerator (you don't even need to press the brake pedal). At least that’s what the "E gen" indicator on the dash seems to indicate. It feels just like coasting in 3rd gear in any other car. Could it be activating more aggressively when the brake pedal is pressed? Nah.The e2o has disc brakes at the front, and there is a vacuum-assisted brake booster present. These are "Power Brakes" - just like every other car on the market. But wait, those systems use the vacuum generated by the internal combustion engine to operate the booster. How does the electric e2o do it? Turns out, this was the problem. There was a small motorized vacuum generator that would spin up every time it felt there wasn't enough vacuum available. This resulted in a huge and sudden power-assist to the booster, which caused the unpredictable braking behavior. How can we be sure? Well, I unplugged the electric vacuum generator and it fixed the problem).Adding to the regenerative braking point, it appears that the 'E gen' disengages at 1-2 km/h, just before the car is about to come to a stop. This means you have to press the brake pedal just a wee bit more to compensate and bring the e2o to a dead stop where you expected it to. This is noticeable in traffic as you slow down and plan to stop close behind another car.Due to the short wheelbase and track, braking hard while taking extremely sharp corners can cause one of the rear tyres to lock up and skid a little. I was enthusiastically pushing along my twisty home-stretch when I experienced this a few times, though I really doubt that the average e2o owner would face a similar situation more than once or twice in their entire ownership.A strip of velcro holds the spare tyre in place. It's extremely easy to access and lift. The jack is mounted with a wing-nut. They are both secured very firmly:Differential on the rear axle (in foreground) with the motor in the background. What's between them is all there is of the transmission:The electric vacuum pump (silver) is connected to the brake booster. When this turns on, it makes the brakes bite suddenly: Last edited by Rehaan : 9th April 2013 at 11:24 .