11k miles of mixed Rex-ing

[FrancisJeffries]

I have totted up 11,300 miles of mixed motoring including long journeys and short.
I have bought 338 litres of fuel and done 11,300 miles in 11 months.
That's 33miles/litre on average. I usually get about 90 miles on a tank-full using Rex alone on long journeys. The longest round trip was 700 miles when I held the charge at 75% on Rex alone. I didn't charge it up once. Nowadays I let the charge fall to near zero when I get home because electricity is cheaper than fuel. Amazingly, most hotels are happy to let me charge using the OUCharger for free :lol: - even when I offer to pay.
The most I ever managed to get into the empty tank (or had to pay for ) was 9.02 litres.
My miles per kWh is 4.7 at present, but falls to 4.4 when I'm doing those long journeys on motorways.

 

[psquare]

Interesting stats from a "high-RExer" ! I would consider myself a "low RExer", with around 4% (6,234 mi) on Range Extender out of our overall 6,501 mi.

What's your electric/REx percentage? I discovered the other day that the i Remote app actually shows you the pure electric miles in "Electric Distance driven" in the graph where it compares it to the community average.

What mode do you usually drive in? After over 4 months of ownership now, we tend to drive in Comfort more and more. Our local journeys rarely require any Eco Pro modes, since most days we do no more than 40 mi per day. Yet, it still makes sense to economise, as this is one of the prime objectives of the i3, IMO.

Your mi/kWh are looking good - we're now averaging at 4.0 mi/kWh, with tyres are at the correct pressure.

 

[redbarn]

Thanks for sharing your information.

We have 2 homes that are 500 miles apart and I have been reticent to use the I3 to do the journey.
I've read of many people doing 200/300 mile journeys but your 700 mile trip has convinced me to give it a try.
There is a level 3 charger about 300 miles from the start so that would be a place to eat lunch (if it is working)
The I3 would run on battery at each end of the trip but I have been leary of Rexing it all the way between.

 

[jadnashuanh]

The REx is a moped motor...designed to loaf along for extended periods of time. It is much less stressful on an ICE to run at relatively fixed speeds verses varying all over the place when hooked up to a transmission and vehicle directly. Here, it is just turning the generator, and vibrations and noise can be more easily controlled because the speeds are known, helping to reduce the annoyance of it running and the wear and tear. The only issue you may have without 'breaking' the code to enable the REx sooner is if you are climbing long grades at speed when the battery level is nearly depleted. Sometime later this year, BMW will offer a s/w update that will take the route's elevation changes into account and enable the REx sooner, when conditions would merit it, and still be within the CAFE rules, eliminating most of those issues. TO take advantage of it, you'd need to enable a route so the car knows where you intend to go...normally not an issue, even if you don't need it, especially if it is someplace you regularly go...you can save it or retrieve it from the recent list rather than having to enter it manually each time.

I'm probably spoiled...if I had to travel that far, I find it much more comfortable (but more expensive!) to use my ICE. On trips like that, I can go over 500-miles without having to search for an EVSE or a gas station at the necessary intervals making that portion less stressful in case one is either down, in use, or some such thing. With the REx, you would need to stop about once an hour. IT may not take long, but you may not find gas stations at the intervals needed open at the time you need them, so may need to do it more often. Maybe relaxing to stop and take a stretch, but not the most efficient in time. Even a CCS stop would need to be nearly 30-minutes, and forget EVSE stops if you plan to make any time.

 

[FrancisJeffries]

I don't have a record of the number of miles on Rex, but it's only used on longer journeys where I get about 10miles/litre, so I guess that we've done around 3,400 miles using it. It might seem a lot, but I took a conscious decision to get the Rex and NOT get a second car for the longer journeys we do. It seems to have worked out OK. (And putting 9 litres of fuel in takes a LOT less time than putting 80% charge in with the DC rapid charger - which I therefore didn't bother to get.)

As far as the miles/kWh are concerned, we use Comfort, but I notice that the iRemote app says we're on 3.8 (the same as the community), whereas the car says 4.7! The analysis only ever shows the results for the last journey, however short. The app is crapp.

We don't have range anxiety at all, but we do need range awareness for the longer journeys. But don't forget we're in the UK, and we take full advantage of being able to switch the Rex on and off whenever the battery is less than 75%

 

[psquare]

I don't have a record of the number of miles on Rex, but it's only used on longer journeys where I get about 10miles/litre, so I guess that we've done around 3,400 miles using it. It might seem a lot, but I took a conscious decision to get the Rex and NOT get a second car for the longer journeys we do. It seems to have worked out OK. (And putting 9 litres of fuel in takes a LOT less time than putting 80% charge in with the DC rapid charger - which I therefore didn't bother to get.)

I agree with Tom Moloughney in saying that owning a REx can mean that you actually drive more electric miles than someone who owns a BEV and an ICE, simply because you might still choose the REx for journey distances where you otherwise would have used the ICE. However, as Jim says, if you don't have the time then constant filling up (5 mins) or CCS charge (25-30 mins) can be too compromising. On my recent trip from Germany back to England I found the perfect mix between CCS and REx, I thought. I made 3 CCS charges and 1.5 REx topups on a 420 mile journey. We tend to use our ICE (Nissan Qashqai) whenever we a) need 5 seats or b) need more storage.

As far as the miles/kWh are concerned, we use Comfort, but I notice that the iRemote app says we're on 3.8 (the same as the community), whereas the car says 4.7! The analysis only ever shows the results for the last journey, however short. The app is crapp.

Yes, I've noticed the differences between car and app. As a software developer, this kind of thing bugs me! I agree with you re the app being crap. Surprises me that some people come on this forum and complain about, say, a lack of automatic seat adjustment or heated steering wheel. To me however it's the i Remote app and ConnectedDrive website that really lets the side down.

We don't have range anxiety at all, but we do need range awareness for the longer journeys. But don't forget we're in the UK, and we take full advantage of being able to switch the Rex on and off whenever the battery is less than 75%

I fully agree with that. We've become more aware of where we need to go the next day and plug the car in according to that. I've also started including public chargers more into my planning, especially if the car has lower SOC, as it means it charges quicker up to 80%, especially on CCS.

 

[epirali]

Actually I mentioned that the app is inaccurate and I have seen the range estimate jump around by 10-20 miles while car just sits in the garage. And that is shows an incorrect range during charging (drops after charging completes). But I was met with the same response as any of the other comments fwiw.

 

[janner]

epirali

I would suggest that you don't focus too much on miles predicted but on how much charge you have. If all four bars are solid then you have 18.8kWhrs available. Times this by your average miles per kWhrs (which you can find on the display or in the app) and you have your 'typical' range. Adjust mentally if you are going to drive differently to how you normally do - faster, slower, etc.

 

[epirali]

epirali

I would suggest that you don't focus too much on miles predicted but on how much charge you have. If all four bars are solid then you have 18.8kWhrs available. Times this by your average miles per kWhrs (which you can find on the display or in the app) and you have your 'typical' range. Adjust mentally if you are going to drive differently to how you normally do - faster, slower, etc.

I understand and agree. I am not. I was pointing out the software bugs. This more of an issue without a built-in precise SOC, because in order to estimate range I always used miles travelled (reset) vs SOC. That is the best way I have found in my other BEVs.

But without this we can only rely on the rough 4 bars and the Guess-O-Meter. And a software bug that reads out jumps of 10-20 miles statically is not what I call acceptable.

 

[psquare]

But I was met with the same response as any of the other comments fwiw.

It must be hard, walking around with that HUGE chip on your shoulder.

 

[epirali]

But I was met with the same response as any of the other comments fwiw.

It must be hard, walking around with that HUGE chip on your shoulder.

No not really, how about you? Its interesting you felt you had to respond to a minor part of the comment, no?

I was simply pointing out that there are people who don't respond well to any kind of comment they don't like. Thanks for illustrating my point.

 

[mindmachine]

epirali

I would suggest that you don't focus too much on miles predicted but on how much charge you have. If all four bars are solid then you have 18.8kWhrs available. Times this by your average miles per kWhrs (which you can find on the display or in the app) and you have your 'typical' range. Adjust mentally if you are going to drive differently to how you normally do - faster, slower, etc.

Actually around 19.6 to 19.9 kwh after the July update. BMW made more battery available for use.

 

[janner]

I think the moderator need to sort out epirali and psquare. I know who I side with but you (the moderator) need to sort this out.

 

[janner]

mind machine - I haven't seen an update here in the UK. Any more info?

 

[epirali]

epirali

I would suggest that you don't focus too much on miles predicted but on how much charge you have. If all four bars are solid then you have 18.8kWhrs available. Times this by your average miles per kWhrs (which you can find on the display or in the app) and you have your 'typical' range. Adjust mentally if you are going to drive differently to how you normally do - faster, slower, etc.

Actually around 19.6 to 19.9 kwh after the July update. BMW made more battery available for use.

That is interesting, didn't know thanks. I think they may have done something similar with the i8 usable capacity.

 

[janner]

epirali

I would suggest that you don't focus too much on miles predicted but on how much charge you have. If all four bars are solid then you have 18.8kWhrs available. Times this by your average miles per kWhrs (which you can find on the display or in the app) and you have your 'typical' range. Adjust mentally if you are going to drive differently to how you normally do - faster, slower, etc.

Actually around 19.6 to 19.9 kwh after the July update. BMW made more battery available for use.

Do you have any more information on the 19.6 to 19.9kWhr update. When was it made available and how do you get it?

 

[jadnashuanh]

Warmer temperatures make our batteries 'look' bigger. Check that same menu item in the middle of winter, and my guess is that the value will be smaller. While possible, I'm not sure it actually was a software change to make more of the battery usable (i.e., make the buffers smaller), it's just a function of the current weather. Check again come winter time. What the latest s/w updates do provide is a reworked algorithm on the remaining range to help make it more accurate.