Driving style

[Bloggsy]

Hi folks - I'm keen to get members' views on this.

My commute has changed, for the immediate future at least, and I now travel 55 miles per trip (obviously 110 miles to get to work and then back home!). This breaks down to 15 miles on A class roads at the start, 25 miles on a motorway, and then 15 miles on A class roads at the end of the journey (the A class roads are a mixture of 30, 40, 50 and 60 mph).

I start the day with a full battery and I don't have a re-charge point at work, so I usually end up with 'zero' on the guessometer by the time I've started down the motorway.

I'm now starting to experiment with 'charging' the car on the motorway part of the trip, but that decreases the fuel economy and I end up with 'zero' by the time I stop at work (and obviously when I start the return journey).

Would just driving the car normally, and letting the car regenerate 'normally' help increase the fuel economy? Not using the 'charge' function on the motorway would obviously increase the average mpg, but I'm not sure the 30% buffer would assist much for the rest of the journey (to and from work)?

Or, should I continue to 'charge' the car on the motorway and use the EV power gained on the A class roads? I should also mention that I will have to use the 'charge' function on some of the A class roads given I'll end up travelling 30 miles altogether in between the trips on the motorway so I will spend longer using the 'charge' function with the lower mpg.

Thoughts, anyone?

Cheers

Bloggsy

 

[michael8554]

There are myriad opinions on CHRG and SAVE.

There are graphs in the Tech Section that suggest there is a Sweet Spot or Area for running the ICE, between 40 and 60mph.

I would CHRG on the 25 mile motorway section, where you can maintain a steady speed.

Then start CHRG again when it becomes necessary on the return journey, gaining only enough charge to get home empty.

B0 and coast as much as possible, increase B to hold the car at a safe speed on descents.

There's probably a SAVE scenario, but I'll leave that to others.

 

[jaapv]

I would -simplistically - just run the car on charge on the motorway and in Eco mode on the slower bits, always taking care to arrive at the charger empty.

 

[Bloggsy]

Thanks guys - having read other posts re driving with Charge or Save, I was conscious there are differences of opinions but it was the affect on the fuel economy when running the ICE I was most interested in!

It seems, the consensus is to use Charge on the motorway, despite the lower mpg so I'll go with that!

It's a shame there aren't more public charge points available!

Cheers

Bloggsy

 

[michael8554]

You shouldn't fixate on "lower mpg", you have to use the ICE on your journey, and that is that.

 

[littlescrote]

You shouldn't fixate on "lower mpg", you have to use the ICE on your journey, and that is that.

Correction - you have to use the ICE on 'some parts of' your journey. During those parts when you do have to use it, it might make sense to use any excess capacity available to put a bit of charge back in the battery that can be used at those times when the ICE is otherwise not needed, e.g. the 30mph sections where the ICE is 'overpowered' and therefore inefficient (it will actually cycle on and off).

It's not as straightforward as saying that Charge on the motorway is best, it may be that Charge on the 50 and 60 mph sections is more efficient as the ICE will be on and can be directly coupled to the wheels (indicated by the Orange power flow arrow between Engine and Wheels) but has a bit of spare capacity at those speeds that can power the generator. At 70mph (or whatever speed you drive at on the motorway) the engine will already be working slightly hard and there may not be any efficiency gain by working it harder to power the generator as well so Save mode might be the better option (to neither charge nor use the battery).

Do some experiments, refer to the efficiency graphs mentioned above to help inform those experiments, and let us know the outcome.

 

[jaapv]

It is not only about fuel efficiency, it is also about keeping a sufficient SOC to meet requirements further on. BTW, charging from "excess capacity" is misleading. The extra power needed for charging when the ICE is running at partial load does consume fuel!

 

[Bloggsy]

Hi folks - thanks again for all the contributions!

I'll do some experimenting and see how it goes. Thus far, I'm only managing 3 return trips (using Charge on the motorway sections only) before I have to fill up with petrol and my fuel gauge is showing just above 'zero' and my guessometer is at 60 miles.

I'll update once I've done some more trips.

Cheers

Bloggsy

 

[ThudnBlundr]

Don't get too hung-up about the various modes. Remember that the car will automatically charge itself for a while when the battery is empty: when the range has increased slightly, it will then switch to EV and run without the ICE till it's empty (30%) again. Then it will charge again and go through the loop again. It's called the hysteresis loop, and the car will go round and round that loop unless you do something different. So on your journey, the car will be charging the batteries some of the time and using EV some of the time whatever you do. The thing is that it doesn't know your overall journey profile, so will just go through that loop whatever the conditions.

All that CHRG does is to run the charge phase of the above without switching to EV till the battery is nearly full or until you turn it off. Apparently the trick is to run CHRG when the ICE is at its most efficient, and use EV when it's least efficient. So using CHRG in parallel mode above 40mph is good, and using EV when it might otherwise be charging in series below 40mph is also good. That's what I try to do. However that is theoretical, and I've not see any concrete evidence that it does actually improve economy.

So you can try to improve economy by playing with the setting like I do, but the car seems to do a pretty good job without our intervention.