Be careful to the filling stations.
The second filling station after the curve, going to Accra (I don't remember the name).
The managers are mixing petrol with cheap products in order to increase their profit.
It can really damage your car.
Take petrol to other filling staations, to be sure take petrol on the left side of the road, when you are driving towards Accra
When I travel around Ghana on my motorcycle I always stop at the SHELL station by the airport in Accra and purchase a few containers of dry gas/fuel.
I try to only buy gas at SHELL or TOTAL gas stations. If you're off the beaten path and purchase fuel at other stations I've found that there is a good chance that there may be water in the gas. You will know this when your engine loses power and you can barely maintain an idle even while working the accelerator. Stop your engine and add the dry gas to your fuel tank. Re-start your engine and keep working the accelerator until your engine's idle stabilizes. Then you can resume your journey.