95 or 98 Octane .... ? (Runs for cover)

[½cwt]

7 hours ago, ½cwt said:

Bottom line is you get a bigger bang at a more efficient place in the cycle of the engine.  As to cost effectiveness and all that, that is an individual choice, but as @plynchy says if it is what Porsche recommends, even if the manual says you can use 95 if necessary.  Why live on only 2000 calories a day when ideally you should be on 2500 (as an adult male) for a heathy diet?

@Stuart21UK my second sentence above???

[½cwt]

15 minutes ago, Stuart21UK said:

Mine does 172mph top speed, doesn't mean I drive it at that speed though so you could also ask

'Why buy a car that does 172mph, and not do it?'

Anyway the proper answer is why does it need 97ron when it runs fine on 95ron?

As a daily driver (more in the 1st 6yrs than now) why spend 10-30p per litre more than I need to when my own measurements proved very marginal mpg improvements?

If you have a garage queen, and do a low mileage then you go ahead and pamper it....for me it unnecessary, so I dont feel the need to  

Besides you may use only 50% of max speed but you probably use 80% of in gear acceleration regularly or do you put a stop under your throttle for that?  And probably similar proportion of cornering performance from time to time too.  And what tyres do you run per @McDonald's observation?  Michelin PS4 may be?

Economics and daily driver argument is different as I have acknowledged already.

[Stuart21UK]

7 hours ago, McDonald said:

Smoother running & longer engine life?

Porsche recommend it, perhaps for a reason.

You probably buy top quality tyres, you could run on-ditch finders to save a few quid.

It's a mindset.

N rated tyres or not?

The non-N rated dont have to be less suitable...could still be premium brand and as good as N rated, no?

presume you use the recommended washing powder as per the label that the washing machine manufacturer says too?

always shop at Waitrose, only buy Hugo Boss etc...

 

snake oil  

Edited August 8, 2021 by Stuart21UK

[Stuart21UK]

6 hours ago, ½cwt said:

Besides you may use only 50% of max speed but you probably use 80% of in gear acceleration regularly or do you put a stop under your throttle for that?  And probably similar proportion of cornering performance from time to time too.  And what tyres do you run per @McDonald's observation?  Michelin PS4 may be?

Economics and daily driver argument is different as I have acknowledged already.

50% of max speed or 80% of blah blah...that proves the point - You, nor I need 100% 

Therefore IF 97ron gave 100%, 95ron is sufficient for 100% of my/your motoring!

 

tyres? N rated Goodyears as opposed to PS4, and your point?

[Stuart21UK]

7 hours ago, ½cwt said:

@Stuart21UK my second sentence above???

2500 calories for the 'average' male adult not every male adult surely?

[Menoporsche]

7 hours ago, Stuart21UK said:

As a daily driver (more in the 1st 6yrs than now) why spend 10-30p per litre more than I need to when my own measurements proved very marginal mpg improvements?

Highlighting this as I'm not sure the newer members are aware of your measurements. I certainly remember the effort you put into them.

Stuart put his spreadsheet where his mouth was and did the math, has now taken the decision for himself. If you guys think differently for your cars - up to you. 

[DaveEFI]

10 hours ago, Menoporsche said:

Highlighting this as I'm not sure the newer members are aware of your measurements. I certainly remember the effort you put into them.

Stuart put his spreadsheet where his mouth was and did the math, has now taken the decision for himself. If you guys think differently for your cars - up to you. 

Yup. I'm one who likes hard data rather than gut feelings. If you decide to buy something more expensive with a posh brand, you have already decided it will be better. Human nature - and what advertisers know very well. Subjective tests should be conducted blind. So you don't know what petrol you're using. Or better still, log the results over an extended period.

It may give you peace of mind to use the most expensive fuel, of course. How you spend your own money is your choice.

[EXY]

10 hours ago, Menoporsche said:

Highlighting this as I'm not sure the newer members are aware of your measurements. I certainly remember the effort you put into them.

Stuart put his spreadsheet where his mouth was and did the math, has now taken the decision for himself. If you guys think differently for your cars - up to you. 

Spreadsheets are all very interesting BUT my own experience of improved MPG from using Super unleaded was gained from a Rover 100 of all things.

We zero'd the miles EVERY fill-up (we still do hence I know our Hyundai Tucson's OBC is about 4-5 MPG optimistic on every fill) and the car went up by about 5 MPG. I didn't need a spreadsheet,unless a notebook counts, to tell the MPG had improved.

But IIRC I have mentioned it before the car just felt nicer to drive, less hesitation, felt smoother etc. So IMHO nicer to drive equals worth it and more MPG is a brucie bonus. Probably the best argument is that even Mrs Exy could notice the difference and this is a woman who would struggle to realise she had four flat tyres! Remember this was on a 1.1 litre super mini.

Another interesting discussion is under drive pulleys. They don't give any measurable advantage other than your 'butt dyno' and yet I am quotable as saying they are the best engine modification for the money, IMHO of course.

Sooo it is my view that super unleaded has advantages that justify the additional cost;

Better MPG in my personal experience across a varied range of vehicles. 

Car just feels nicer to drive.

Possibly better fuel additives over 95 but who knows. Our family used Dipetane many years ago.

Snake oil suggests worthlessness but the advantages are worth the extra expense to me.

[Scubaregs]

As previously stated, I saw a 3/4 mpg increase using super in the GT86. I didn't spreadsheet it as I didn't have to, I ran the car to and from work only for a month on each and any other journey was used by my then DD mini.

If a manufacturer says to use a certain ron or above, that's what I use. My S1000r is recommended to use higher ron according to BMW. 

I do 12,000 miles pa for work, nearly all motorway, so even at 30p extra a litre and around 40 mpg it costs me around £250 a year to use the fuel recommended by the manufacturer. If I see an extra 3/4 mpg then I suspect that £250 all but disappears, if I don't then I'm happy to pay £250 and use the fuel type recommended for the car.

 

Edited August 9, 2021 by Scubaregs

[Stuart21UK]

14 hours ago, Menoporsche said:

Highlighting this as I'm not sure the newer members are aware of your measurements. I certainly remember the effort you put into them.

Stuart put his spreadsheet where his mouth was and did the math, has now taken the decision for himself. If you guys think differently for your cars - up to you. 

thanks for this, did think of pointing it out but didnt want to edit the post again  

3 hours ago, DaveEFI said:

Yup. I'm one who likes hard data rather than gut feelings. If you decide to buy something more expensive with a posh brand, you have already decided it will be better. Human nature - and what advertisers know very well. Subjective tests should be conducted blind. So you don't know what petrol you're using. Or better still, log the results over an extended period.

It may give you peace of mind to use the most expensive fuel, of course. How you spend your own money is your choice.

indeed, free choice to all  

3 hours ago, EXY said:

Snake oil suggests worthlessness but the advantages are worth the extra expense to me.

my comment was a little provocative I'll admit, designed to get a bite (and you won) it was either that or one relating to PDK to elicit a reaction from someone  

I was feeling a little naughty at the time, back to good boy status now  

2 hours ago, Scubaregs said:

As previously stated, I saw a 3/4 mpg increase using super in the GT86. I didn't spreadsheet it as I didn't have to, I ran the car to and from work only for a month on each and any other journey was used by my then DD mini.

If a manufacturer says to use a certain ron or above, that's what I use. My S1000r is recommended to use higher ron according to BMW. 

I do 12,000 miles pa for work, nearly all motorway, so even at 30p extra a litre and around 40 mpg it costs me around £250 a year to use the fuel recommended by the manufacturer. If I see an extra 3/4 mpg then I suspect that £250 all but disappears, if I don't then I'm happy to pay £250 and use the fuel type recommended for the car.

 

I'll admit I saw an increase to mpg too, just didnt want the pain of the £ to get it, plus living in a village with one BP station and a screwy pricing strategy (one occasion IIRC Super was 30 pence per litre over UL) it was not a guarantee I'd actually save/break even).

each to their own and all that 

[Scubaregs]

7 minutes ago, Stuart21UK said:

 

I'll admit I saw an increase to mpg too, just didnt want the pain of the £ to get it, plus living in a village with one BP station and a screwy pricing strategy (one occasion IIRC Super was 30 pence per litre over UL) it was not a guarantee I'd actually save/break even).

each to their own and all that 

My normal bike ride is up through Glencoe, then round into Oban, then one of 3 routes home. I get Tesco 99 ron a mile from the house, by Oban I need to refuel again and the nearest for premium is close to Taynuilt which I would struggle to get to with whats left in the tank. So it's the good stuff on the way up, regular on way home.

[Stuart21UK]

7 minutes ago, Scubaregs said:

My normal bike ride is up through Glencoe, then round into Oban, then one of 3 routes home. I get Tesco 99 ron a mile from the house, by Oban I need to refuel again and the nearest for premium is close to Taynuilt which I would struggle to get to with whats left in the tank. So it's the good stuff on the way up, regular on way home.

🤣

[McDonald]

51 minutes ago, Scubaregs said:

My normal bike ride is up through Glencoe, then round into Oban, then one of 3 routes home. I get Tesco 99 ron a mile from the house, by Oban I need to refuel again and the nearest for premium is close to Taynuilt which I would struggle to get to with whats left in the tank. So it's the good stuff on the way up, regular on way home.

Even snake charmers have to be pragmatic. 😀

[EXY]

4 hours ago, Stuart21UK said:

 my comment was a little provocative I'll admit, designed to get a bite

That is weird, that was what I had been thinking

But I didn't want to exploit anyone

PDK baiting is for amateurs, N rating is where it's at Stu

[Stuart21UK]

3 hours ago, EXY said:

That is weird, that was what I had been thinking

But I didn't want to exploit anyone

PDK baiting is for amateurs, N rating is where it's at Stu

I thought about suggesting a meet up with someone who's using Super and testing the 'better performance' theory but it would be unfair if they had PDK, it being faster more efficient etc etc 

[zcacogp]

6 minutes ago, Stuart21UK said:

I thought about suggesting a meet up with someone who's using Super and testing the 'better performance' theory but it would be unfair if they had PDK, it being faster more efficient etc etc 

I quite agree - that would be most unfair on the person with the PDK-equipped car. 

Perhaps a fairer drag race would be a manual model on normal against an otherwise identical model with PDK on super. 

<LightsBlueTouchpaperAndStandsBack>

 

😄

[EXY]

16 hours ago, Stuart21UK said:

I thought about suggesting a meet up with someone who's using Super and testing the 'better performance' theory but it would be unfair if they had PDK, it being faster more efficient etc etc 

Hmmm providing there were some twisty bits the car fitted with N Rated tyres would easily make up any deficit