Keeping track of my MG4 (efficiency)

[hojnikb]

Someone was feeling optimistic yesterday! I even turned on ECO mode, just for those magic extra km.

This is the result of a trip I did during the past weekend, which consisted of 253 km, on something equivalent to A- and B-roads.

It was hot (around 27ºC), there were 3 of us inside the car and the AC was on the whole time, on 22ºC.

The average speed was 64 km/h (~40 mph) and the consumption 12.2 kWh/100km (5.1 mi/kWh), which is frankly good and the reason why the GOM was feeling so optimistic.

The car was still showing 36% of battery remaining (141 km) at the end of the trip.

That's pretty good! I was able to hit 123Wh/km the other day. 95% highway driving at 95km/h and this was roundtrip (one way i was able to get 114Wh/km).

Next i'm going to test with summer tires (currently running winters with petty high rolling resistance) and with more pressure (this test was around 2.5bar).

I'm keen to see how low can you go. I think i still have atleast 5-10% more efficiency on the table, so 110Wh/km roundtrip shouldn't be too hard to hit in good conditions. With 51kWh gross and 47kWh usable (a bit of degradation and some bottom buffer i suspect) i think over 400km is achievable on highways using slow lane and have some buffer left over.

 

[MG4JP]

That's pretty good! I was able to hit 123Wh/km the other day. 95% highway driving at 95km/h and this was roundtrip (one way i was able to get 114Wh/km).

Next i'm going to test with summer tires (currently running winters with petty high rolling resistance) and with more pressure (this test was around 2.5bar).

I'm keen to see how low can you go. I think i still have atleast 5-10% more efficiency on the table, so 110Wh/km roundtrip shouldn't be too hard to hit in good conditions. With 51kWh gross and 47kWh usable (a bit of degradation and some bottom buffer i suspect) i think over 400km is achievable on highways using slow lane and have some buffer left over.

Your figure is even more impressive, considering it was at 95 km/h.

The best I've accomplished so far was:

• 11.4 kWh/100km on a 90 km roundtrip (averaging 50 km/h);
• 10.0 kWh/100km on a 26 km roundtrip around the city (33 km/h).

Given my location, I'm always on summer tyres and I currently have my tyre pressure set to a value which makes it change on the display from 2.5 to 3.0, depending on how cold/hot it is (we've been having high temperature fluctuations).


As for the best possible results, I'd say Bjørn Nyland's test is a good benchmark on that. Images below were taken from one of his videos:

 

[hojnikb]

Your figure is even more impressive, considering it was at 95 km/h.

The best I've accomplished so far was:

• 11.4 kWh/100km on a 90 km roundtrip (averaging 50 km/h);
• 10.0 kWh/100km on a 26 km roundtrip around the city (33 km/h).

Given my location, I'm always on summer tyres and I currently have my tyre pressure set to a value which makes it change on the display from 2.5 to 3.0, depending on how cold/hot it is (we've been having high temperature fluctuations).


As for the best possible results, I'd say Bjørn Nyland's test is a good benchmark on that. Images below were taken from one of his videos:

Yeah, i think it was pretty good result also. Do note that it was around ~22-23C (although i had AC blasting the whole time). And i'm running 16s (205/60R16) so that might help me a bit as well. And of course this was behind a truck most of the time, so i had some aero advantage as well.

Im considering buying either e.primacy or e.ziex tires as both have excellent rolling resistance.

 

[MG4JP]

First post updated, with April's data:

Period	Distance (km)	Efficiency (kWh/100km)	Average Speed (km/h)	Up Time
April 2025	1110	14.7 (4.23 mi/kWh)	34	32:14

Current overall combined efficiency: 15.1 kWh/100km (4.11 mi/kWh)

 

[Anon70]

I was updating my Excel sheet today and realised I had not been tracking the difference between what a charger records as energy sent to the car and how much energy the car records as being stored in the battery (based on % charge). Have updated this and can see a 220kW discrepancy since I have owned the car, of which only 106kW was paid for and at about 8p per kWh that is a loss of about £8.40. Also impacts the efficiency stats which are closer to 3 miles/kWh using the battery figures not the charger figures.

 

[wattmatters]

I was updating my Excel sheet today and realised I had not been tracking the difference between what a charger records as energy sent to the car and how much energy the car records as being stored in the battery

Yes, all my numbers are based on the energy I "pay" for be it DC fast chargers, home charging, destination charging etc.

So my long term average of 17.55 kWh/100km is the energy supplied, not the DC drive energy consumption which would be something less than that.