Hello friends. After my first 10 months with my HCII , after driving 14.000 Kms (about 9000 miles) almost all of them inside Athens , a very difficult city to drive with many uphills and downhills , i am very pleased to have managed to keep my overall average fuel consumption to about 5.1-5.2 l/100km (about 45 mpg ) Perhaps many of you find it rather dissapointing number but i assure you i am extremely pleased , given the fact that almost all of theese kilometres are to and from work with a rather tight time schedule so i must sacrifise many times fuel consumption for time efficiency.
One think i am still concerned about my car , after all theese months , is the way to drive in a constant uphill road. If you have to drive uphill for a long time what is the best way ( meaning less fuel consumption ) to drive :

1. your foot steady as a rock to the gas pedal , minimising machine effort as possible to keep a steady speed , no acceleration , no slowing
2. a short pressure to the gas , release the pedal for the car to slow down and then back to the gas

Assuming the uphill is long enough , what do you think is the best way to drive ? also , from th point of fuel consumption , better to drive in N or S ?

 

I do my climbs in S. climbing a steep and long mountain in D just drain the battery too fast and then your mileage is in the dumps.

ks

 

I wouldn't say that either of those is the best. In my experience, the best technique it to "drive with load" where you keep the load on the engine constant, even though you bleed speed as the hill goes on.

Pretend you're going up a 1km hill. You would enter that hill at ~20km/h faster than your normal cruising speed (hopefully because you just came off a downhill). Then use your instant fuel display to lock in on an consumption (say 25mpg*) and keep it there the whole way up as you lose speed.

Ideally, you will reach the top at 20km/h slower than your normal cruising speed. If you find that you slow down too much, try more gas next time (say 20mpg) and keep it steady the whole climb--even if you accelerate a little at first. If you are not bleeding off enough speed, try starting out with less gas and maintaining that pressure the whole way up.

This doesn't work very well when you are starting out from a stop though--in those times, I accellerate until I get to my minimum crusing speed and then maintain even pedal pressure and engine load.

This works best on multi-lane roads where people can pass you though, and in areas where you aren't worried about speeding tickets for being a little over the limit--I don't know how well that will work for you in Athens. Good luck!

* Sorry about the MPGs, my mental metric conversions only go so far

 

Thanks for the tips friends. Kristian . no problem with mpg , i have used to them so long in this and other USA dominated forums

As for the tips , Kevinstop's way is rather better for long uphills in the highway , were i really find that my battery is drained very quickly no matter what i do.As for the city driving , kristian your way is maybe better if it is a road without many stops and starts. I will work more on this and i will come back with my remarks. BTW any of you knows a way to avoid electric assist in long uphills , were you know that after a while your battery will be empty and your mileage will be launched in space ? There is a steep uphill road in a highwway in greece about 20 km long ( about 12 miles). Whatever i do my battery is empty after the first 6-7 km and then my mileage is dead. I must confess i have not tried the same road with S but i have noticed that the mpg for a given speed is higher in S than N so , from the point of fuel consumption S is worst. Has anyone any idea how to deal with this huge uphill ?

 

I'm don't know if there have been any software updates for the Euro version of the Civic, but the latest update in the US has changed the assist behavior on hills for me. Originally, my car would have a high assist affinity on the first hill going into the mountains and drop down to 1 or 2 bars of battery pretty quickly. With the update, the assist affinity is actually higher when the pack is above 5 bars, but after I hit four bars it relies on the engine more (higher RPMs) and the car rarely drops below 3 bars.

When the engine is reving higher, the economy drops, but it doesn't get into forced regen as quickly as it used to before the update so the economy doesn't drop quite as much. Since you have an '09, I'm not sure if this upgrade would even be applicable for your car--it is for '06-'08 in the US.

"S" seems to be the best way to decrease the assist affinity, but it seems like it wants to regen more when you back your foot off the pedal which robs you of speed. For that reason, I haven't been a big fan of "S" for climbing. I haven't given it a fair chance on my new commute though (180m gain over 9km).

 

For my car the battery never drops below 4 bars , but at 4 bars i see forced regen so , it is actually the same ( i have seen less than 4 bars only at very high temperatures last summer , in any other case 4 bars is the less i have ever seen , but it is also the limit for the forced regen to begin)
In fact the way you describe your car's behaviour after the update is exactly the way my car is behaving from the beggining. I agree with you that N is better than S but unfortunately this doent solve me the problem of how to avoid assist. There should be a button to the car to allow the driver to deactivate electric assist , rigth ?

 

I would LOVE this! People developed a modification for the original Insight to do this, but the HCH II's IMA system has proven to be a tougher nut to crack. There were some people trying to do this a few years ago, but I think they have pretty much given up on trying to build a switch like this for the HCH.

It's kinda a shame that there aren't as many people moding the Civic as the Prius. It would be nice to have some aftermarket software upgrades to improve fuel efficency for those of us who are willing to sacrifice a little driveability to get higher MPGs.

 

I totally agree with you friend. But there is another problem with these modifications. This could be a reason for the local daeler ( at least in Europe ) to cancel the warranty. Here in Greece HCHII comes with 8 years of warranty in the hybrid system. I wouldnot take the risks to loose it by a modification. Instead i would love to see theese things made from mother HONDA .

 

It would be nice to be able to stop assist and to force an auto-stop. There are times when we as the driver know about the future that the car does not know, like the hill continues for 10km or we're going to be stopped for a couple of minutes.

A big frustration I have is when I stop I ease off the brake to not stop harshly but if I ease off too much, the engine restarts and then won't stop again. So I end up sitting at red light with the engine running and that's very annoying.

I also occassionally go over a hill that's about 1200m, basically climb up one side and then down the other. I seem to do ok one way but the other way I end up with a nearly full battery before the big decline and it doesn't take long before the battery is full and regen stops on the decline. It would be nice to try to drain the battery somewhat before that big decline.

 

100% agree with you. And it is only one button. Unfortunately Honda didnt made it. Hopefully in the next civic