SkyActiv + 99RON fuels?
Discussion
I have a new Mazda 6 2.0 SE-L NAV tourer/estate, and asked this of Mazda UK when I took delivery of the car. A month later, they've kindly ignored me twice and not sent any answers. So, I'm wondering if anyone here knows.
Given that the engine is N/A one would imagine 95RON was all it was capable of using to full benefit (at least as standard). However, the high 14:1 compression ratio surely means higher octane fuel would lead to benefits? Or is 14:1 just the limit for 95RON fuel and 99RON would be a useless addition? The fact the engine is lowered to 13:1 for the slightly lower octane US market seems to support this, but I'd still like to know.
Basically is there any benefit in adding 99RON super as opposed to 95RON regular unleaded? I'd normally be the first to opt for chucking in the cheapest standard fuel but with 14:1 compression and knock sensors I'm just wondering if the ECU has the propensity to try to advance timing to go with it? TIA.
Given that the engine is N/A one would imagine 95RON was all it was capable of using to full benefit (at least as standard). However, the high 14:1 compression ratio surely means higher octane fuel would lead to benefits? Or is 14:1 just the limit for 95RON fuel and 99RON would be a useless addition? The fact the engine is lowered to 13:1 for the slightly lower octane US market seems to support this, but I'd still like to know.
Basically is there any benefit in adding 99RON super as opposed to 95RON regular unleaded? I'd normally be the first to opt for chucking in the cheapest standard fuel but with 14:1 compression and knock sensors I'm just wondering if the ECU has the propensity to try to advance timing to go with it? TIA.
I generally find benefits to be had in using higher octane fuels in everything I own. I have one car specifically mapped to suit 99ron, so have no choice with that vehicle.
We have a Lexus IS300 auto which is significantly more sprightly when it's had a couple of tanks of momentum through it, much more eager to kick down, etc. Never checked to see if the mpg has changed though!
And my work van, Ford Connect 110, can't comment on the performance aspect of it, but 10% improvement in economy when using Shell nitro diesel, as opposed to supermarket stuff.
Get used to your car and the way it performs on lower octane stuff, try and take accurate mpg readings, and then do the same with higher octane fuel. I'd run a couple of tanks of the high octane fuel through it first, then start to check consumption, etc. If it's better on fuel, the chances are it's also performing better, even if it's not obviously apparent from the drivers seat.
We have a Lexus IS300 auto which is significantly more sprightly when it's had a couple of tanks of momentum through it, much more eager to kick down, etc. Never checked to see if the mpg has changed though!
And my work van, Ford Connect 110, can't comment on the performance aspect of it, but 10% improvement in economy when using Shell nitro diesel, as opposed to supermarket stuff.
Get used to your car and the way it performs on lower octane stuff, try and take accurate mpg readings, and then do the same with higher octane fuel. I'd run a couple of tanks of the high octane fuel through it first, then start to check consumption, etc. If it's better on fuel, the chances are it's also performing better, even if it's not obviously apparent from the drivers seat.
Thanks for the reply. I have been tracking my MPG with Fuelly since I picked up the car, and have now switched to Momentum 99 to see how it goes (the Tesco fuel vouchers have helped!). So far I'm getting 49mpg on short dual carriageway runs and city MPG is up between 40 and 42mpg overall. Previously it was hovering between 37mpg and 39mpg depending on traffic that week, so thus far we're looking at a 8% to 10% improvement in economy for fuel that only costs 4.6% more.
On the plus side, my butt-dyno says the car feels much smoother low down and feels more eager to pull and cruise. I put it down to placebo until I noticed the dashboard's gear change indicator. Until now it asked for 5th gear at 40mph and wouldn't want you in 6th until 50mph or so, depending on load and acceleration, throttle position etc. Since running Momentum 99 through, it now asks for 6th gear at 40mph and 5th gear at 30mph so that's quite some improvement. On 95 RON the car juddered/struggled in 5th at 30 but now it sits quite happily and even pulls.
So far I'd say it was worth it, and even if the differences aren't huge they're still statistically significant and the car feels nicer to drive. The higher RON fuel paid for itself in this case, so I'll stick with it.
Cheers.
On the plus side, my butt-dyno says the car feels much smoother low down and feels more eager to pull and cruise. I put it down to placebo until I noticed the dashboard's gear change indicator. Until now it asked for 5th gear at 40mph and wouldn't want you in 6th until 50mph or so, depending on load and acceleration, throttle position etc. Since running Momentum 99 through, it now asks for 6th gear at 40mph and 5th gear at 30mph so that's quite some improvement. On 95 RON the car juddered/struggled in 5th at 30 but now it sits quite happily and even pulls.
So far I'd say it was worth it, and even if the differences aren't huge they're still statistically significant and the car feels nicer to drive. The higher RON fuel paid for itself in this case, so I'll stick with it.
Cheers.
There's another thread running at the moment, basically asking whether there are any benefits to be had by running " branded " 95 octane over the supermarket equivalent........I can't comment on that, but, as you seem to have discovered for yourself, I'm pretty convinced that options like Momentum99 and Shell Nitro offer a benefit, both in performance and economy, even taking into account the higher initial purchase price. I do regular long trips between Newcastle and Southampton, it's easier to see the advantages in some respects.
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