Best fuel for dull motorway driving

[Aj1]

Basically I've got a 120 mile drive to Guildford tomorrow morning (a journey I've made and will make many times) but it's the first time I'm doing it in the zed, so the question is is it worth filling up with with something like v-power of just normal fuel for motor way miles? Am I going to getting any benefit with the high octane for just a constant speed for 2 hours?

Any words of wisdom would be grand

[mmm-five]

It's designed to run on 95-98RON fuel anyway, so you won't do any harm by putting in the cheapest 95RON fuel you can find - although try to buy it from a busy garage as you'll get 'fresher' fuel, which is more likely to be at it's peak performance.

Super won't make much difference on a motorway cruise anyway, it's more for extracting the last bit of power out of the engine - e.g. if you're going on a driving tour, track day, etc.

[jodale]

This subject comes up a lot and everyone has a different opinion. I put 89 octane in mine and never had an issue. I have tried the 91 octane several times and I cannot find any difference.

[canman]

during my recent euro tour which included lots of motorways i put in the highest octane available, usually 98-102 and returned 35 mpg at a steady 80 ish mph . not sure how much better it would have been on 95 octane. not bad for a 3 litre i thought.

[Jembo]

Makes a noticable difference in my A3 diesel, though can't say have noticed any economy difference in using the 98 Ron in the Zed, seems keen to please whatever tipple goes down it's throat.

[Ewazix]

I recently ran my 2.5 SE on V power for a few weeks motorway commute and general driving and saw a 1 - 1.5 mpg improvement, which probably just about pays. And it's not scientific but the pick-up under load up regular hills I drive is definitely a little sharper with reduced tendency to start pinking. This makes sense as the higher octane allows more timing advance in the ignition mapping.

No other performance benefits noticed though.

[cj10jeeper]

I'll be doing a 260 mile round trip of which a total of 4 miles is on non motorway (boring drive or what...).
98 ron in it now and everytime. Better mpg and breaks even as a result.

That said it will be of no harm at all to just run it on 95 as that's in its acceptable range, but you'll save all of 75p

[roofless]

I used to put 95 in mine but now use v power and have to say i am getting better mpg, i don't think i've changed my driving style either. It was nearly 2.5 hour drive to goodwood for the festival of speed and the car returned better mpg on v power than i've had in the past on 95 over similar trips. Not scientific i know.

[Half Colin]

I ran mine for a month on 95 then a month on 98 and the mileage and usage (long trips and short trips) was about the same. I must admit that from all the hype and write ups I was expecting better MPG on the 98 but from the calculations it was exactly the same.

[sars]

Well my 420 motorway miles a week are completed on 95 grade fuel my indicated lifetime average is 38.1, for motorway driving I just don't see the point in going the super route, if you want to save fuel stick to 70 mph.

On an empty motorway where you don't have to lift off often, the benefit of speed over journey time is significant, on a busy motorway with lots of braking speed becomes less relevant.

[roofless]

if you want to save fuel stick to 70 mph.

People drive above 70mph in blighty

[imp75]

I was always under the impression that higher octane lead to better fuel efficiency. I always use shell 97 but mainly cos it seems to give a smoother delivery to my four potter!