Have recently bought a '99 Legacy Outback in the UK and wonder what fuel to use. Inside the filler 'flap' it says that only 'super plus' unleaded fuel be used. In the uk, this is 10% more expensive than regular unleaded fuel.
What happens if I use the regular fuel? Why should I use the 'Super plus'? Could I do any damage using regular?
Thanks
Dug
The Legacy's got a knock sensor so it should cope but the extra fuel consumption probably outweighs the saving
Super plus is higher octane than normal unleaded. If you run it on normal
95RON you could get pinking and that will knacker the engine.
The Japanese Legacys are designed to run on 100RON fuel, the European ones on 95 or 97RON and the US ones on 95RON. It's the same engine/ECU. However the fuel map in the ECU is different. You can run your UK one on 95RON premium unleaded quite safely, but you'll find it lacking in torque when under load compared to running it on 97RON super, which is what the base map is set for.
The knock sensor will cause the ECU to adjust the timing and fuelling to cope with the lower octane fuel.
I run my Japanese import Legacy GTB twin turbo estate on Optimax or Super, and have never had any problems with pinking. I've run it with octane boost a few times and can confirm the ECU adjusts it's fuelling. It produces 280bhp when on 100RON, but more like 260bhp on Optimax (according to rolling road figures, so take with a pinch of salt). Still plenty of power for an estate car :)
I'd say use normal unleaded for day to day running, but if you're going to be driving in big hills, or fill the boot with lots of stuff, then stick Super or Optimax in. Optimax is 79.9p a litre here in York, so not that much more than normal unleaded (oddly though, 15 miles away in Goole it's 84.9p, and in Leeds it's 77.9p)
Rich.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.