BMW i8 - long-term review

First question in my head before I bought the i8: it’s a ten year old hybrid, there’s a lot to go wrong, what do I need to be wary of? Type that question into Google and AI will happily feed you every forum horror story. But I have a better solution. Matt Fisher is a master technician at BMW UK, and has been working on i8s since they were new.

I take mine down for a once over. Even here i8s are a rare sight, so Matt calls the apprentice technicians over to have a poke around underneath. I feel strangely defensive as four people crane their necks into its underbelly. My first thought: it’s not as pretty underneath as it is up top.

It seems previous owners might not have been that careful over speed bumps. Nothing catastrophic, but the fabric panels (they help to reduce road noise) bear the scars. And given the service history paperwork I’ve got lists new underbody panels as a previous line item, they’re not the first set it’s had.

But no horror stories under there, just some puzzlement about why the wheel nut bolts have corroded and a possible query over a small oil leak where it looks like the filter has been over tightened. Up top, only the stuff I’d already spotted - rubber boot seals starting to peel away, exposed door wiring where the shroud has perished and missing cover panels for the bonnet releases.

The really interesting stuff comes when we plug into the OBD port. I had no idea how much data modern cars retain. Soon after I got KF17 ZDS I gave it a clean and afterwards I put the windscreen wipers down in the wrong order. 

The next time I started it, the first thing it did was sweep the wipers to rearrange the wiper order. Clever stuff, I thought. But it also logged that as a fault code and now Matt picks it up in the data logger. Everything is in here from which key has been used to open the doors to what mode it’s been driven in, from full schematics to torque settings for every bolt. It’s astounding.

We go back through the car’s history and there’s only one red flag - a big four year gap in the service intervals between 2021 and 2025, where the mileage went up from 22,000 to 46,000 with no maintenance until it was 2,200 miles overdue. We delve deeper, Matt looking at everything from engine oil to brakes to electrics, but the car has seems to have shrugged off this inattention.

One worry going forward is the B38 engine’s timing chain, which apparently likes regular oil changes. “I’ve known them to last 120,000 miles,” says Matt, “but you need to keep an eye on them from 70-80,000 onwards.”

My main concern had been the drive battery, so I leave the car with them for a full SOH (State Of Health) check, where the battery is completely drained, charged, drained and charged again. The news come back - it’s 100 per cent. Zero degradation from norm after 10 years. More evidence that EV batteries last well.