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My wife and I are both retired, and love to go exploring around Arizona. Today was a 152 mile round trip from our home in Green Valley up to the top of Mt. Lemon north of Tucson.


Our Niro EX - actually my wife's, and not a plug in - is less than a month old, so not broken in, but here is what we did today. The run from home to the edge of Tucson is 28 miles of freeway that we averaged 70mph on. I think of this as a flat run, but it is really downhill from 3000 ft elevation to 2500 ft. Easy drive.



Then we drove thru Tucson toward the foothills of Mt Lemon. This is typical city driving for about 15 miles with lots of stop lights, traffic, and a little construction. The AC ran all the time. When we stopped for coffee, I noticed 61 mpg for that part.


Climbing the mountain is a different story. In about 20 miles of switchbacks and 6-7-8-9% grades, the Niro performed beautifully. I anticipated needing Sport mode, but never did. It climbed from 2500 ft to 9100 ft easily. It climbed over 6500 ft at 25 to 35mph with no big effort. The speed limit is 35, and many places that is way too fast.


We had lunch, hiked around a little, looked for birds and took some photos, and then headed home along the same route. Down the mountain with all the switchbacks required Sport mode. I was in 3rd gear almost always, and sometimes pulled it down into second. But I only had to touch the brakes a little, and the handling was really great. The Sport mode does an interesting thing. I pulled over a couple of times to let tailgaters by, and when I started up again, it shifted thru first and second, but then stayed in third when I was tearing downhill at over 30.


Going back thru the city and back down the freeway to get home, I ended up at 50.9 MPG for the trip. This is hardly the good mileage so many people are getting, but I doubt many make the kind of drive I did. I didn't know ahead of time what to expect on the mountain and was pleasantly surprised. My Niro is not a candiate for the Pikes Peak Rally, but does a good job on a pretty good mountain ride.
 

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Nothing wrong with your mpg. You might have done better without sport mode down the mountain, perhaps using regen with CC. Engine braking is useless, even in sport. I went down 5 or so miles down a state park mountain at 20 mph (about as fast as the conditions, 25 mph speed limit). Round trip, HEV battery was max full at the bottom, and mpg average stayed the same as the tank average for the round trip.
 

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I recently drove my Niro to Vegas from orange county, and while it was fine most of the time there are a couple very long, somewhat steep hills and the Niro was really struggling on them. I mean it made it up without any real trouble, but it had to downshift a couple times to do it, and the engine was just screaming. I don't know what RPM it was because there's no tach, but it would have to keep upshifting and downshifting; downshifting and keeping it at very high RPM until it got up to speed, then upshifted until there wasn't enough power in that gear to maintain speed, and it would downshift again.

This only happened once on the way there, and once on the way back, and both on the same hill I'm pretty sure - the big one just south of the CA/NV border on the 15. It might have been better at a lower speed, but we were just keeping up with traffic, cruise was set at 75 I think. It's not a "problem" really, it's just a result of trying to maintain a set speed up a hill when the requirements for maintaining that speed on that hill are more than the drivetrain can provide in a higher gear. I do wish the Niro had more battery power, which would allow it to run on battery in normal driving conditions more of the time without switching over to the gas engine, and provide more torque for situations like this one. But for the vast majority of the time, it's fine. On my last tank I averaged 52 mpg (via the Fuelly app, not the in-car estimate) and I can't complain about that.
 

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At one time, car gearing was designed so you never had to downshift to go up hills. Those cars got terrible mileage. The modern trend is ever more gears so you can effectively be in overdrive to match any highway speed while cruising. But under load, like up a hill or accelerating briskly from a cruising speed, yes, downshifts are to be expected. Screaming engines is not a bad thing (although perhaps more soundproofing would be good), but the sound of a very efficient low powered motor.

I have a 700CC motorcycle tuned for efficiency (I'm getting 78 mpg in the summer as long as I don't exceed 65 mph) with a 6 speed transmission. I sometimes have to drop four gears to make a fast pass at 40 mph on a two lane. Annoying perhaps, but motorcycles that can pass quickly (or climb steep hills) without downshifting get about half the mpg I get. Just as a by the way, my bike has about 40 HP - faster than most cars because it is lighter, but some bikes with the same size engine develop well over 100 HP.

You pays your money and takes your choice of rides!
 

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I recently drove my Niro to Vegas from orange county, and while it was fine most of the time there are a couple very long, somewhat steep hills and the Niro was really struggling on them. I mean it made it up without any real trouble, but it had to downshift a couple times to do it, and the engine was just screaming. I don't know what RPM it was because there's no tach, but it would have to keep upshifting and downshifting; downshifting and keeping it at very high RPM until it got up to speed, then upshifted until there wasn't enough power in that gear to maintain speed, and it would downshift again.

This only happened once on the way there, and once on the way back, and both on the same hill I'm pretty sure - the big one just south of the CA/NV border on the 15. It might have been better at a lower speed, but we were just keeping up with traffic, cruise was set at 75 I think. It's not a "problem" really, it's just a result of trying to maintain a set speed up a hill when the requirements for maintaining that speed on that hill are more than the drivetrain can provide in a higher gear. I do wish the Niro had more battery power, which would allow it to run on battery in normal driving conditions more of the time without switching over to the gas engine, and provide more torque for situations like this one. But for the vast majority of the time, it's fine. On my last tank I averaged 52 mpg (via the Fuelly app, not the in-car estimate) and I can't complain about that.
I have noticed the PHEV adds the motor to the ICE when hill climbing before shifting down. It seems to never shift down unless I floor it. This may be unique to the PHEV because its battery is much larger, large enough to assist all the way up the mountain.
 

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yes, downshifts are to be expected.
Right, I didn't say I wasn't expecting it to downshift.

Screaming engines is not a bad thing
Yeah, it really is; especially in this case, where the engine is just sitting at what has to be very close to redline, screaming its way up a hill. It's absolutely a bad thing to just sit near redline under load for long periods of time.

I sometimes have to drop four gears to make a fast pass at 40 mph on a two lane.
Making a pass is one thing, staying at redline is something else. All I'm saying is that it would be nice to have a little more torque so sitting at redline wouldn't be necessary in situations like that.
 

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Yeah, it really is; especially in this case, where the engine is just sitting at what has to be very close to redline, screaming its way up a hill. It's absolutely a bad thing to just sit near redline under load for long periods of time.
Whether this is a bad thing or not depends on several factors, including:

  • What is the Niro's ICE designed RPM limit and how does that compare to the maximum RPMs the ECU will allow?
  • Is the cooling system robust enough to handle the additional heat from the ICE running at max RPM?
  • Does the oil have sufficient margin to handle the increased loads at max RPM?
Assuming Kia's engineers did their homework I wouldn't worry too much about the engine running hard for extended periods. I would think that would be a natural trade-off with a hybrid system. You can get away with a smaller ICE without issue most of the time, but the thing will be required to thrash when the situation demands it. Design in sufficient margin and you should be good to go.
 

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Let me get this straight. You have an ultra-economy car and set the cruise at 75 going up a 4000 ft mountain and you are wondering why the engine is working hard? Are you for real?

If you don't like the upshifting just shift it into sport mode. Sport mode will hang onto the lower gear better. And NO the engine revving is not a bad thing. What's bad is being in too high of gear for the load. That will rip your transmission out eventually and kill your engine. The reason is that if you have a heavy load such as driving up a steep hill, the power required to do this is basically the same whether in a high gear or low gear. In the high gear however both the engine is spinning disproportionately slower which reduces both oil and water cooling due to the pumps running slower (perhaps new fangled electronic ones adjust automatically but the standard oil pump is shaft driven). This creates excessive heat and wear. Ditto for the transmission. It'll tend to overheat. But luckily this little beauty of a transmission is really a manual in disguise meaning more durable and less heat issue.

If you were doing that hill with a CVT it would sound like the vehicle was going to fly apart.


To ask the vehicle to sit at cruise at 75 mph up such a grade and then complain it was revving engine then shifting excessively shows a few things. For your scenario you have unrealistic. Put the vehicle in sport mode and take the cruise off. Hold a constant pedal position instead. Let the engine 'breathe' a little. However it would be nice if the thing had a straightforward tachometer. That would probably make people feel more comfortable.
 

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The principle reason the Niro gets such good gas mileage is because the ICE runs the atchison cycle. Almost all ICE run on the Otto cycle. The basic efficiency difference is 40% vs 30%.

The trade off is less torque and horse power (e.g. ~100 vs ~140Hp). This is offset by the motor which adds back 43hp (HEV) or 60hp (PHEV). This combination works well for acceleration of a mile or so for the HEV and 25 miles for the PHEV (if fully charged). OK for passing but a little under powered for long mountain grades (unless you have a fully charged PHEV).
 

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Ive noticed here in the SF Bay Area, using CC going up hills yields a better MPG then manually holding the pedal down. The computer system is pretty intelligent, it will apply more battery/electric power when needed. Youll notice the power needle staying in the ECO (green) zone more often.


Down hill, I disable CC if I want to REGEN, sometimes I just leave CC on.
 

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Let me get this straight. You have an ultra-economy car and set the cruise at 75 going up a 4000 ft mountain and you are wondering why the engine is working hard? Are you for real?
No. Where do you think you saw me say I was wondering WHY it was happening? I know WHY it's happening. Maybe go back and read what I said again.

If you don't like the upshifting just shift it into sport mode.
It's not about whether I like upshifting or not.

And NO the engine revving is not a bad thing. What's bad is being in too high of gear for the load.
Again, this is not what I was talking about. The gear is not relevant because it's an automatic and I'm not shutting it manually. It's obviously not going to be in a gear that's too high for the load. And I didn't say the engine revving is a bad thing, I said the engine running at close to redline under load for extended periods of time is a bad thing. That doesn't mean I think the engine is going to explode, it just means that if you ask Kia they're not going to tell you that it's a GOOD thing to keep it close to redline under load for long periods of time. And there are multiple reasons for that.

But this is still neither here nor there; I pretty clearly said that is was not a "problem" per se, and that I just wish it had more battery power to provide more torque for situations like that.

To ask the vehicle to sit at cruise at 75 mph up such a grade and then complain it was revving engine then shifting excessively
I don't think you read my comment all the way through.

Put the vehicle in sport mode and take the cruise off. Hold a constant pedal position instead.
All sport mode does is adjust throttle sharpness and use both the gas and electric motors at the same time. But in normal mode it does the same thing depending on load, so putting it in sport mode wouldn't change anything. It was already using both the gas and electric motors. And holding the throttle at the same position would still result in upshifting and downshifting, because the issue is not having enough power and torque to handle the load smoothly.
 
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