[telemeister]

Considering buying a 2013 Jimny which comes in 2 models - JX and Sierra.
The different Suzuki websites are a bit confusing - but reading between the lines it
looks like the JX uses standard Unleaded, but the Sierra is supposed to use Premium Unleaded (95).

Can anyone confirm that this is correct, and if so any idea what is different in the Sierra
to make it need 95. On paper the engines look the same.

Thanks

Steve

[christover1]

Timing, tuning etc is usually set to a particular fuel. Most people I know find 95 and 98 better in all their Suzukis.

[Gwagensteve]

I can assure you they are the same motor. The difference between the two versions is trim only AFAIK - there will be no difference in fuel requirement.

I'd be very surprised if a Jimny required 95 Octane.

As for cars running better on higher octane fuel - this will be the case for modern motors with knock sensing, but for old school, non-knock sensed motors, using higher octane fuel is a waste of money unless the ignition timing is advanced to accommodate the increased octane.

In very simple terms:

Effectively, higher octane fuel burns for longer. If the engine has a knock sensor, the ECU will advance timing until it detects knock and then back it off a smidge, and continually do this - thereby maximising the advantage of high octane fuel. With knock sensing, I've always found it cheaper to run cars on the highest octane fuel available (that contains no ethanol)

Without a knock sensor, the engine doesn't know that there is any ability to increase advance, so the longer burn is wasted. This has been proven numerous times.

I don't know which suzuki motors are knock sensed, I imagine all M motors are, most J motors, but I don't think any G motors are.

I got trapped in the vortex of adjusting timing to suit octane with my 660 motor. It was a waste of time, because without the ecu checking for knock, I'd chase my tail - on a cold night the car would take heaps of advance, on a stinking hot day, very little advance over the baseline for 91 octane was possible. Granted, this was a turbo engine and therefore probably more octane sensitive than a carby atmo car, but still, I think it's relevant experience.

Steve.

[shep]

I have a 2013 jimny sierra with the 95 octane only sticker in the fuel flap. I just put anything in it and it still works, doesn't seem to affect power or economy however to be honest I don't bother keeping track of fuel use.

[Gwagensteve]

There you go - 95 octane it is then.

I'm sure you can use anything you like, engine warranty not withstanding.

Steve.

[telemeister]

Here's an example of what I mean..

All the ads for the JX say Unleaded regular. All the ads for Sierra say Premium

http://www.westpointautos.com.au/new-cars/jimny

Similar things on other sites - although the Suzuki Jimny brochure doesnt mention
a specific fuel type for either model.

[Mike57]

My 2009 model has the same 95 RON sticker inside the fuel flap. M13A engine.