Autovolt Magazine

Wk9. Motorway EV driving

On a particularly cold summer evening, I decided to put the electric range of the Kia Optima PHEV (Optima Prime) to the test. It has always stated 31-miles on the display, although I’ve managed to eke 32-miles with relative ease after driving carefully and at town speeds up to 30mph.

In traffic or urban driving then, the 31-miles range has been accurate and, interestingly, so has the manufacturer stated range of 32-miles. However, that’s all well and good, but what about if you venture along motorways? Surely this would impact the range negatively and offer far less practical electric driving?

Setting off from St Albans with Sandy in Bedfordshire as my destination, a round trip of 70-miles depending on the route taken. The routs consists driving up the A1, a few hills and a couple of roundabouts. There’s are slower 60mph then 50mph sections after Biggleswade and toward Sandy, but otherwise 70mph is the legal limit. The car is capable of 75-80 mph in electric mode before the petrol engine takes over, so really not an issue in the UK.

Kia Optima PHEV

There’s really nothing to it. I decided not to pay attention to the range and to simply drive as I normally would. Accelerating along the slip road to reach motorway speed reduced the range by a couple of miles, which I didn’t think was a very good start. However, by the Hitchin junction, the range was approximately half and what I expected it to be. Traffic was light and smooth progress was easy. In some ways, this possibly hindered my range, as I was able to travel at 70mph the whole way unhindered.

Upon reaching Sandy, the range dropped to 0-miles and I feared I hadn’t made it. However, by the time I came to a stop in Sandy, I’d travelled 29-miles and reached my final destination just off the A1. What’s more, the battery still had 16% charge remaining, clearly demonstrating it was capable of more and I can only conclude it would have been easily able to cover an additional 3-miles to reach the predicted 31-miles. In theory, I’d have been able to travel another 4.6-miles on electric until the battery depleted to zero. And it’s worth mentioning that ‘zero’ on the dash is of course not zero at all, as there’s still some battery charge kept in reserve so as not to damage the battery.

Overall, it’s an impressive result. I had wrongly predicted the car’s electric range was only really good for urban environments and the car proved me wrong. EV range – in summer at least – proved roughly the same as could be expected around town. I believe this to be the result of the electric motor’s more efficient power delivery and maintaining a constant speed, rather than accelerating and stopping as is the norm in a town. Consequently, my average overall MPG has risen back to nearly 100mpg once again. It’s not taken too much effort either and despite numerous local journeys (no more than usual) I’ve also been to Norfolk and back on petrol. So, a real-world 99mpg is very much possible thanks to the plug-in power and it’s worth remembering most people are doing less than half that.