66 mile round trip, 600 ft elevation change, 55mph: doable?

[kg4bec]

So I don't have my LEAF yet (two weeks to go!) but I've been tracking my mileage for the last 3 months and only a few times would I have exceeded the expected range of the Leaf. So I'm curious about a trip I did recently: 66 miles, most of it at 55mph, and within 50 feet of my starting elevation. I did encounter a hill that meant a 600 ft climb and descent down the other side over the distance of about 5 miles. Otherwise the trip was unremarkable.

My gut reaction tells me that this trip is doable, also based on various reports here on the forum. Any thoughts?

Cheers, Bert

 

[TomT]

That should be easily doable with range to spare. I routinely do trips more demanding than that with ease.

So I don't have my LEAF yet (two weeks to go!) but I've been tracking my mileage for the last 3 months and only a few times would I have exceeded the expected range of the Leaf. So I'm curious about a trip I did recently: 66 miles, most of it at 55mph, and within 50 feet of my starting elevation. I did encounter a hill that meant a 600 ft climb and descent down the other side over the distance of about 5 miles. Otherwise the trip was unremarkable.
My gut reaction tells me that this trip is doable, also based on various reports here on the forum. Any thoughts?
Cheers, Bert

 

[kg4bec]

Thanks Tom, I appreciate your input!

Cheers, Bert

 

[DaveinOlyWA]

at 55 mph you should have a good 20-25% SOC left over. with any hill, play it to your advantage. Regen is normally not recommended but on a hill that size, its probably unavoidable. if you can, hit the top of the hill as slowly as you can and let gravity bring you back up to speed but not too quickly.

regen is waaay less efficient but much better than nothing. whatever you do, try not to brake. use eco and brake feathering to control your speed.

 

[thankyouOB]

easily done.
i do 50-mile roundtrip daily, at 80% with 2-3 bars left at the end.
I try to drive no more than 62 mph.
usually go around 50-60 due to traffic for 80% of the way, and 30-40 on the streets, the rest of the way.

 

[TonyWilliams]

As everybody said, you won't break a sweat on this trip.... unless it's really, really cold !!! Or there's a 50mph wind on the nose. Or you battery has degraded significantly (maybe in 5 or 10 years).

Otherwise, happy motoring.

 

[johnr]

If it is cold and you use the heater, that will cut in to your range significantly. However, assuming you're going at a fairly consistent speed and the use of the heater is also consistent, the car's range meter (Guess-O-Meter) is actually fairly accurate - especially as the range approaches empty. Without using the heater, you'll make the trip easily. With the heater, not so sure. But if you have to, you can squeeze out several more miles by raising the thermostat or turning off the heater.

 

[kg4bec]

Thanks for the great responses!

Re. The temps, we're in the south here so I really don't eect it to get too cold, and as it's a 2012 LEAF it'll have the heated seats and steering wheel which is expected to be more efficient than the space heater in the 2011 model.

Re. The speed, the only section that is interstate is literally 3 miles and most of the interstates around this area are currently under construction so are speed limited to 55mph anyway! LOL. I do understand the need to keep speeds constant as much as possible for best range since you use energy every time you speed up and you gain a little bit back whenever you slow down... But obviously you cannot avoid changing speeds up or down according to traffic etc. but my plan is to drive it pretty normally and keep an eye on the bubbles to gauge energy use and regen.

I'm still figuring out the regen vs. coasting argument. I know regen causes you to slow down but it seems to me that it is a waste not to recover some of that energy when you have to slow down anyway. I just don't get how coasting could be better than regen because you don't get any energy back when you coast. However, I know there are other threads that cover this so I have more reading to do. And hopefully in about two weeks, I'll have direct experience to draw on!

Cheers, Bert

 

[foobert]

Here's a data point for reference: round-trip from San Jose to San Mateo by way of 280. It's a very hilly freeway as seen by the one-way profile:

One-way data:
[*] cumulative of 3300 ft gain, 2800 ft loss
[*] 33.3 miles

Did the trip with the cruise set at 60 MPH, and would free-wheel down the hills by holding my foot on the throttle to neutralize the traction motor. No HVAC. Brief seat warmer usage. Intermittent wipers one way. Head lights the other. Averaged 3.8 miles/kw over the 66.6 mile round trip. Had 13 miles left on the GOM and just hit the last bar on the SOC meter before returning.

I did plug in for about 1 hour of L1 at the destination, with half of that time spent pre-heating the car. At most it added 3-4 miles of usable charge.

 

[TonyWilliams]

I'm still figuring out the regen vs. coasting argument. I know regen causes you to slow down but it seems to me that it is a waste not to recover some of that energy when you have to slow down anyway.

Here's the simple answer. Imagine, if you will, a deserted highway that you're driving along at 60mph. Flat, no wind, at sea level, straight as an arrow. There's a stop sign one mile away (5280 feet). To drive that mile at 60mph will take 0.256kWh.

If you waited until just 200 hundred feet from the stop sign, and slammed on the brakes from 60mph, hopefully you can see the energy wasted through the brakes. But, what's not as immediately apparent is that you consumed 5280-200/5280 of 0.256kWh of energy, or 0.2463kWh during that mile.

So, let's drive 60mph for 3/4 of that mile, and coast in neutral for 1/4 mile to a complete stop. Total energy consumed is 3/4 of 0.256, or 0.192kWh burned during that mile.

Now for the regen question. Clearly, we can't regen for 1/4 mile, because that's how far is had to coast. So, let's split the difference, and regen for 1/8 of a mile. So, 7/8 of 0.256kWh is burnt (0.224kWh) plus whatever percentage of regen you can get back in that 1/8 mile. As you can see, we already burnt more energy than coasting, but can we get back that 32 watts to match coasting?

The simple answer is no.

 

[evnow]

Easy. Infact you can do that with a 80% charge in summer.

 

[LEAFfan]

I'm still figuring out the regen vs. coasting argument. I know regen causes you to slow down but it seems to me that it is a waste not to recover some of that energy when you have to slow down anyway.

Here's the simple answer. Imagine, if you will, a deserted highway that you're driving along at 60mph. Flat, no wind, at sea level, straight as an arrow. There's a stop sign one mile away (5280 feet). To drive that mile at 60mph will take 0.256kWh.
If you waited until just 200 hundred feet from the stop sign, and slammed on the brakes from 60mph, hopefully you can see the energy wasted through the brakes. But, what's not as immediately apparent is that you consumed 5280-200/5280 of 0.256kWh of energy, or 0.2463kWh during that mile.
So, let's drive 60mph for 3/4 of that mile, and coast in neutral for 1/4 mile to a complete stop. Total energy consumed is 3/4 of 0.256, or 0.192kWh burned during that mile.
Now for the regen question. Clearly, we can't regen for 1/4 mile, because that's how far is had to coast. So, let's split the difference, and regen for 1/8 of a mile. So, 7/8 of 0.256kWh is burnt (0.224kWh) plus whatever percentage of regen you can get back in that 1/8 mile. As you can see, we already burnt more energy than coasting, but can we get back that 32 watts to match coasting?
The simple answer is no.

+1! Great explanation Tony! Coasting can really raise your m/kW h just by noticing the lights at least 1/4 of a mile ahead. Sometimes, I've coasted a 1/2 mile!
Kg, if you want to get even more efficiency with coasting, make sure your tires are at least 40psi. I do mine 5 higher to 41 because I was told by tire experts that you will still have good control and they will wear better. And I have to use a 'professional' air pressure gauge (Milton) because I have yet to see any of those air compressor gauges or 'cheap' digital/stick gauges be even close to accurate.

 

[kg4bec]

Hi Tony,

Thank you for that excellent explanation. I think it makes sense now. And I think I see where the points of contention can be... Very rarely do we get to drive in perfect conditions to allow us to coast to a stop in the way you describe, and in fact it had me wondering if there was any point in regen! ...until I realized that in real-life traffic we have to speed up and slow down as needed to stay with traffic lest we become hazards on the road. And where regen is useful is that we can at least recover some of the energy that was used. Nowhere near as much as was used to get us up to speed, but some, at least, that would otherwise be wasted as heat in the disc brake pads.

Cheers, Bert

 

[TangoKilo]

I'm still figuring out the regen vs. coasting argument. I know regen causes you to slow down but it seems to me that it is a waste not to recover some of that energy when you have to slow down anyway.

Here's the simple answer. Imagine, if you will, a deserted highway that you're driving along at 60mph. Flat, no wind, at sea level, straight as an arrow. There's a stop sign one mile away (5280 feet). To drive that mile at 60mph will take 0.256kWh.

If you waited until just 200 hundred feet from the stop sign, and slammed on the brakes from 60mph, hopefully you can see the energy wasted through the brakes. But, what's not as immediately apparent is that you consumed 5280-200/5280 of 0.256kWh of energy, or 0.2463kWh during that mile.

So, let's drive 60mph for 3/4 of that mile, and coast in neutral for 1/4 mile to a complete stop. Total energy consumed is 3/4 of 0.256, or 0.192kWh burned during that mile.

Now for the regen question. Clearly, we can't regen for 1/4 mile, because that's how far is had to coast. So, let's split the difference, and regen for 1/8 of a mile. So, 7/8 of 0.256kWh is burnt (0.224kWh) plus whatever percentage of regen you can get back in that 1/8 mile. As you can see, we already burnt more energy than coasting, but can we get back that 32 watts to match coasting?

The simple answer is no.

I appreciate the math, it adds more perspective to my driving. I find myself however, driving in ECO about 3/4 of the time around town, as it "trains" my lead foot into being more energy efficient...

 

[TonyWilliams]

Now, let's put things in the perspective of a downhill one mile highway, with a stop sign at the bottom.

Coasting is not possible, because we would never stop (at least not at the stop sign). So, we need to use regen as much as possible over friction braking to stop.

For those situations, I usually put the car in ECO mode, and slowly bring in the brake pedal as needed to minimize friction braking.