i3 Rex - is this the (only) car that solves the tax question
Discussion
Z4MCSL said:
I am reading a LOT of stories of people driving ONLY on petrol for extended journeys stopping every 80 miles.
Are they all making it up, or is this some different model. Or am I on LSD right now?
The detuned motorbike engine puts out 34 bhp and charges the battery, the battery powers the electric drive motor.Are they all making it up, or is this some different model. Or am I on LSD right now?
You can drive at a limited speed with a depleted battery this way but the tank holds 9 litres, this information is from wiki.
Z4MCSL said:
I am reading a LOT of stories of people driving ONLY on petrol for extended journeys stopping every 80 miles.
Are they all making it up, or is this some different model. Or am I on LSD right now?
What they are trying to say is that the wheels are always driven only electrically. The Range Extender only charges the battery.Are they all making it up, or is this some different model. Or am I on LSD right now?
AFAIK you the max chargeing rate from REX is approx 22KW so if you hoof it a lot the charge can't keep up with the demand and the car limits stuff.
In practice, I have been to Cornwall and back from London a good few times with zero charging stops but many many fuel stops. You can only activate the REX at 75% and from that point onwards, you’re managing the charge rate of the REX and battery depletion there on.
I’ve got it down to an art form and could probably write a book!
I’ve got it down to an art form and could probably write a book!
Nick, thanks for this, I was hoping to hear from someone who actually had one so thanks! 
So at 75% battery you can drive just on petrol stops - that is interesting.
Under 75% does the petrol become meaningless?
As I am in London and dont have a drive or a chargepoint on my street I would be relying on other chargepoints which can get busy, or other cars can park in the spaces. I dont have one at work either.
So I wondered how low the battery could be whilst you still pootle around on petrol, guessing the answer is not below 75?
Also assuming the petrol engine only maintains the battery level, it cant actually charge it up?
Also, seeing as you are reading this, how have you found it generally and how well does it hold its charge when not driven for a little while?
So at 75% battery you can drive just on petrol stops - that is interesting.
Under 75% does the petrol become meaningless?
As I am in London and dont have a drive or a chargepoint on my street I would be relying on other chargepoints which can get busy, or other cars can park in the spaces. I dont have one at work either.
So I wondered how low the battery could be whilst you still pootle around on petrol, guessing the answer is not below 75?
Also assuming the petrol engine only maintains the battery level, it cant actually charge it up?
Also, seeing as you are reading this, how have you found it generally and how well does it hold its charge when not driven for a little while?
Comments in line below:
Z4MCSL said:
Nick, thanks for this, I was hoping to hear from someone who actually had one so thanks!
So at 75% battery you can drive just on petrol stops - that is interesting.
NP: Yes, although the battery will continue deplete for a number of reasons, for e.g. If you’re driving in winter with the heating on full blast, if you’ve a car full of people, driving above 70mph - so in sum, you have to drive in an energy conservative manner to allow the REX to produce enough energy to maintain the battery’s charge
Under 75% does the petrol become meaningless?
NP: No - ABOVE 75%, the petrol becomes meaningless
As I am in London and dont have a drive or a chargepoint on my street I would be relying on other chargepoints which can get busy, or other cars can park in the spaces. I dont have one at work either.
NP: I did this for the first 3 years of i3 ownership - now I charge from home as we’ve moved house. I live in central London and the REX works OK but doesn’t kick in until you’re going over 18mph and then switches off when you drop below 9mph. As the average speed through central London is often below this threshold, you’re often without REX and depleting your battery. So in sum - do work out where you can charge as you’ll need to.
So I wondered how low the battery could be whilst you still pootle around on petrol, guessing the answer is not below 75?
NP: When the battery depletes to sub 5%, the REX goes wild to try and keep it going - that’s when it really starts sounding like a lawnmower. I don’t usually allow the car to get to this stage.
Also assuming the petrol engine only maintains the battery level, it cant actually charge it up?
NP: Correct - you need an i8 for that! :-)
Also, seeing as you are reading this, how have you found it generally and how well does it hold its charge when not driven for a little while?
NP: Just do it! It took me a while to get my head around it all, charging from lamp posts, managing Rex, wearing 6 layers of clothes in the winter to not use air con - but it’s all good fun and it’s the best car I’ve owned. I own both the i3 and the i8 and they make a cracking pair of cars.So at 75% battery you can drive just on petrol stops - that is interesting.
NP: Yes, although the battery will continue deplete for a number of reasons, for e.g. If you’re driving in winter with the heating on full blast, if you’ve a car full of people, driving above 70mph - so in sum, you have to drive in an energy conservative manner to allow the REX to produce enough energy to maintain the battery’s charge
Under 75% does the petrol become meaningless?
NP: No - ABOVE 75%, the petrol becomes meaningless
As I am in London and dont have a drive or a chargepoint on my street I would be relying on other chargepoints which can get busy, or other cars can park in the spaces. I dont have one at work either.
NP: I did this for the first 3 years of i3 ownership - now I charge from home as we’ve moved house. I live in central London and the REX works OK but doesn’t kick in until you’re going over 18mph and then switches off when you drop below 9mph. As the average speed through central London is often below this threshold, you’re often without REX and depleting your battery. So in sum - do work out where you can charge as you’ll need to.
So I wondered how low the battery could be whilst you still pootle around on petrol, guessing the answer is not below 75?
NP: When the battery depletes to sub 5%, the REX goes wild to try and keep it going - that’s when it really starts sounding like a lawnmower. I don’t usually allow the car to get to this stage.
Also assuming the petrol engine only maintains the battery level, it cant actually charge it up?
NP: Correct - you need an i8 for that! :-)
Also, seeing as you are reading this, how have you found it generally and how well does it hold its charge when not driven for a little while?
The op seems to confuse this with "drive only on petrol".
There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
Caddyshack said:
The op seems to confuse this with "drive only on petrol".
There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
Is there an ideal speed where you could in theory run it on petrol for infinite distance OR is it properly limited? There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
Not seen one for a while now
Welshbeef said:
Caddyshack said:
The op seems to confuse this with "drive only on petrol".
There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
Is there an ideal speed where you could in theory run it on petrol for infinite distance OR is it properly limited? There is no physical connection between the wheels and the engine. The engine is purely an electricity generator. You can drive it over a long distance if you keep filling up with fuel as the engine continues to charge the battery as long as you do not demand too much of the battery as the engine does not produce enough electricity to keep up with demand.
Not seen one for a while now
I think you could deplete the battery and rely on a low rate of charge city driving and use the regen too but not expect huge performance.
I have a Twizy and can get about 10% extra range on a warm day using regen in town driving but 10% of not a lot is still not a lot.
Maybe it's the way I phrased it
Really I am asking if you can drive the car WITHOUT charging it at a charge point...I.e just using the petrol engine to charge the battery. So yes appreciate it would not be the petrol engine driving the wheels but the experience as a user would be that of a petrol car. I.e filling up at petrol stations, not charging at charge points .
It seems the answer is "sort of, it depends" I.e.depending on how its driven the engine can (at best) maintain the battery.
Really I am asking if you can drive the car WITHOUT charging it at a charge point...I.e just using the petrol engine to charge the battery. So yes appreciate it would not be the petrol engine driving the wheels but the experience as a user would be that of a petrol car. I.e filling up at petrol stations, not charging at charge points .
It seems the answer is "sort of, it depends" I.e.depending on how its driven the engine can (at best) maintain the battery.
No you cannot rely on just using petrol in that the battery should not be left in a depleted state for any length of time, so must be charged up. You have to plug it in to gain charge. It is also a heck of a lot more expensive so pointless to run on petrol - around about only 40-45 mpg is achieved. The cost running on electric is around 3-5p per mile.
As the above have said, it is a really enjoyable car to drive. Just take a test drive and you are more than likely going to be hooked in the first 10 minutes. I have only used my Focus RS to get it's MOT done in the 7 months I've had my i3 Rex. Love it. Oh, and I haven't even used a tank of petrol yet, but it has saved my bacon a couple of times knowing I can stretch the electric out to it's limit before getting to a recharging station.
As the above have said, it is a really enjoyable car to drive. Just take a test drive and you are more than likely going to be hooked in the first 10 minutes. I have only used my Focus RS to get it's MOT done in the 7 months I've had my i3 Rex. Love it. Oh, and I haven't even used a tank of petrol yet, but it has saved my bacon a couple of times knowing I can stretch the electric out to it's limit before getting to a recharging station.
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