Morning @Glos-Guy
I tried to replicate your test over 1o0 miles on 60-70 mph roads and 2o miles split at higher speeds. I will split my results into sections.
I purposely left home with a 60% battery, drove in Auto (EV) mode and switch to HEV mode at 57% battery 17 mies remaing EV, when joining a dual carriageway. Although there was a few roundabouts to navigate, the roads were as usual at that time of day fast flowing.
The first 100 miles (60-70mph) saw the battery fluctuate between 56 to 57% (15-18 miles). The conditions noted on the PHEV screen:
Hybrid mode:
1- Engine charged the battery, battery powered the wheels
2- Both engine and battery powered the wheels
Electric mode:
1- Battery powered the wheels, sometimes for a matter of yards, other times a mile or so.
Charging Mode:
Engine powered the wheels and charged the battery – Instantaneous consumption dropped to 20mpg.
Engine fuel mode (this is interesting one)
1- The battery symbol dimmed out and the engine powered the wheels only, but didn’t charge the battery? Although only briefly, I saw this happen three times weird!
Part one of the test, the car more or less mimicked Auto mode after the EV range had ran out, although economy wasn’t has good, as eaving the car in Auto mode for the entire jounrney. The GOM read 41.7mpg.
For test 2, was 10 miles on a faster A road with speeds into the 80’s trying to mimick motorway driving for 10 miles. Whils’t I saw more of the charging mode, I was able able to modulate the accelerator, whilst maintaing the same speeds, I was able to go unto hybrid mode for short distances. Whils’t the battery did charge it charged to no more than 60% for a short time. The same scenario occured with the instantaneous consumption dropping like brick, when in charge mode, although as before the little triangle above stayed at the high 30’s mark.
Test 3 was similar to test 2 apart from pre setting cruise control (which I don’t usually use) into the mid 80’s for the second part of the dual carriageway. This test was ended early after 7 miles as there was traffic plod about however, during those miles the battery had creeped upto 65%. I would expect it would have carried on charging if I had carried on.
Coming home Sunday, it was difficult to maintain the speeds due to farm traffic and your usual Sunday traffic even though it was issing down, so I didn’t attempt it again.
Hope this helps but, happy to carry out this or any test anytime.