Well I have a GP1 2013, now I have clocked exactly 60K, about couple of months back I noticed the oil level drop. And then I refilled oil and ran for more than a month.
Last week I had the check engine light lit up and vehicle went Limp Mode. Immediately I checked with a scanner and it said Cylinder 3 was failing. The local mechanic suggested to replace plugs and do an engine tune up. Then I took it to Stafford Motors Raththanapitiya.
The service advisor immediately suggested that this is a know issue. And they need to replace pistons, rings and some other stuff. The estimate was 160K. Luckily they had stocks with them. I asked them to proceed with the repair. It was a three day work.
Finally I got the vehicle and I feel it's reborn, drive is extremely smooth.
They advised me to use 10w 30 oil and not to rev the engine much during initial 1000KMs.
I hope I have done what's required.
For those who consider buying a GP1. I would say.
It's a great car to drive, you can enjoy every bit of it.
Not very economical in city my one did 10Km/L, but out side the city it easily does 25Km/L
Until this repair came up I have only done a gear oil change as a costly maintenance.
Suspension is bit to the stiff side but generally a comfortable vehicle.
Good luck.