Premium fuel in Honda Hybrids.

[peteo48]

Oh no - not this old chestnut I hear you cry.

I have very sketchy understanding of the internal combustion engine but would I be right in thinking that there is almost no case (if there ever was one) for using premium fuel in the MK4 Jazz (or any other i-mmd Honda powered car)? I base this thesis on the fact that the ICE is primarily used as a generator and will rarely be under any significant load.

Thoughts?

[Kenneve]

I agree, there is no particular case for using premium fuel.
However regarding 'significant load' there are times when the virtually all the engine power is required.
The electric motor is rated at 80Kw (107ps) and the generator will need to power most of that, at times.
Also remember that at speeds above around 45 MPH, the engine can be directly coupled to the motor, for max efficiency, so the engine may again need to work hard, depending on driver demand.

[nowster]

Also remember that at speeds above around 45 MPH, the engine can be directly coupled to the motor, for max efficiency, so the engine may again need to work hard, depending on driver demand.

I think you meant "directly coupled to the wheels". This is usually in an "overdrive" situation.

And the petrol flap specifically says RON 95, E5, E10.

It's very unlikely that the engine is going to be run in a configuration which labours it so much that it might promote pre-ignition.

[Expatman]

It’s a personal choice. In my experience using 97 RON fuel in my last few cars has resulted in a smoother engine and better MPG with more torque on hills etc. I am one of those people who keep a note of every fill and mileage so get a very accurate view on petrol consumption. I tested by doing 10,000 miles with 95 RON and then 10,000 miles with 97 RON and achieved a 5% improvement in MPG, petrol price was slightly more than 5% for upgraded petrol but difference not much and worth it (IMO) for the better drive.
These results were from a 1.2 Tsi Skoda so whether they apply to the Atkinson cycle Jazz engine I don’t know, but I would have thought they would.

[sportse]

I've been using Shell V-Power 99 since new.

It's something I've also always used in my Yaris and Auris hybrids before - the engine and stop/start were definitely much smoother in those using it.

There might be less benefit in the Jazz as it's a generator mostly, but I've been sticking with it due to previous experiences.

You do need to avoid the motorway service stations - I saw V-Power on the M25 for 175p/litre recently 

[Kremmen]

I did a month on month experiment a decade ago using my 1.8 auto Civic and 95RON, 97RON and 99RON it made absolutely no mpg difference or any perceived performance differences.

A similar test between E5 and E10 would be interesting.

[Kenneve]

I think you meant "directly coupled to the wheels". This is usually in an "overdrive" situation.

It's very unlikely that the engine is going to be run in a configuration which labours it so much that it might promote pre-ignition.

I believe my statement to be correct, in that the engine/generator in the situation stated, is coupled directly to the electric motor by a dog clutch, which then obviously drives the wheels.
I agree though, that it is unlikely to promote pre-ignition.

[Lord Voltermore]

F1 racing will use E10 fuel for the 2022 season.  Honda have agreed with Red bull that they will develop the 2021 F1 engine to run on E10.    If its good enough for F1 engines its good enough for me   

Honda have already developed the hybrid atkins cycle engine for E10 . Indeed it may have been designed  from the outset for E10.  These engines are renowned for  fuel efficiency, not torque.

Other fuels may indeed be better in some respects, but I think I read somewhere that petrol cars sold in Europe since 2011 have their engine management systems, and sensors optimised for E10.  They can tolerate  other fuels by changing their timing ,air fuel ratio etc. 
The reason some earlier cars cannot use E10, or dont run as well on it  is they are optimised for other fuel, and cannot alter their management settings enough to cope with E10.   (also high concentrations of ethanol can perish  rubber, certain alloys, soldered joints etc used in older fuel systems but this mostly affects  classic cars) 

IMO its not necessary or cost effective to use anything but E10 .

[Expatman]

Ethanol is hygroscopic so will absorb water from the air. Driven conservatively petrol in a Jazz's tank could be there for a long time so likely to absorb a lot of moisture, not sure if that's good for the engine or ancillaries?

[Jazzik]

Ethanol is hygroscopic so will absorb water from the air.

In France, E10 is common since 2009, in Germany and the Netherlands since 2011. In Brasil since 1976...
I have not heard that the cars in those countries have a petrol tank with a "water sump" and water drain pump...
I happened to drive quite a bit in those countries no, not in Brasil... (before COVID-19) and never noticed any difference between E5 and E10 let alone problems.

[guest9814]

Sorry for resurrection of this old topic
If 95 RON Gasoline is made real 95 RON, it’s absolutely enough for our MK4, in my Country often fuel that reach end point (fuel pump) already have less juice (94-90 RON) sometimes it’s refinery plant fault (one of our 2 plants fined last year as them produce lower grade gasoline then they should), sometimes gasoline fraud and then methanol or something else added to ramp up octane.
And I found in local press from 2008 that in our r country beginning to use  gasoline E5 , but on pumps that never reflected no E5 marked pumps !
I sometimes hear knocks or pops when engine cold,  when I fill gasoline in place’s that I usually not filling up, sometimes this occurs when gasoline sits in tank half months and partly used, when I adding premium gasoline 98 RON this pops or knock’s go away, and on obd2 diagnostics app Car Scanner I see that timing advance goes up when premium fuel added, last time in summer I used pure 98 RON gasoline alone, that time I did trip (fully loaded wit me and 4 passengers) with hills and when I needed to go uphill from Dead Sea to Arad the car crawl up at speed 60km/h(there serpentines and speed limit 60km/h)  where other cars struggled to speed up and I leave them behind.
Dead Sea from TelAviv, 163 km each side full load with A/C elevation up to 477m above sea level from +47m sea level to Dead Sea and back 163km from -420m to Arad +477m sea level back to TA speed ~90KM/H, 2 trips 110km 90km/h, rest with speed 40-50km town. 947 km from 35l, another find that premium good only in summer, when I tried premium gasoline  in winter (+6 degrees C) I actually get bad fuel economy and quickly added 95RON to tank.

[sportse]

I’ve done 8000 miles on super unleaded 99 E0 and 8000 miles since then on ordinary 95 E10 unleaded.

There’s no difference to performance and barely any difference in mpg on the Jazz.

It did make quite a difference on my Toyota hybrids, as they have a petrol engine connected to the wheels through a type of gearbox, rather than the generator in the Jazz.

[guest9814]

Premium 98RON make sense only when 95RON gasoline quality is bad or unavailable, my last tank of 95RON i get best MPG that I seen ever, 3,0l/100km (town) 40-50km/h driving. But after 2 weeks when engine cold it  started to making unusual noises accompanied by engine hesitation, added 14l 98RON gasoline and this rectified the issue.

[Jazzik]

Roman, I suspect that your experiences with the various petrol types do not match the experiences of motorists in (most) European countries.

[Karoq]

Honda (Jazz & HR-Ve:HE)says 95 RON (E10) so why waste your money on higher grades?
I'm now going to shoot myself in the foot.
When Shell introduced V Power many years ago I did an empty to full tank of V Power in my CR-V and it made no difference whatsoever. So I'm with Kremmen!     
Colin.
ex Shell U.K. Retail market.