98 or 95 octane?
- Thread starter RX-78
- Start date
My understanding is that if a car (like ours!) is designed to run at a higher octane you will see a benefit... put 98 in a 95 only engine and the computer spends the whole time mapping it out - making the "explosions smaller" and negating any increased performance... I believe that's what I was told.
Now the sad part... apart from being on a motoring forum on a Friday night... I took the average fuel consumption from a few tanks of 95 RON and then 98 RON, the increase in fuel economy means it's cheaper overall for me to pay the extra per litre. It was shameful made a spreadsheet and everything. I know, I'm a nerd.
Now the sad part... apart from being on a motoring forum on a Friday night... I took the average fuel consumption from a few tanks of 95 RON and then 98 RON, the increase in fuel economy means it's cheaper overall for me to pay the extra per litre. It was shameful made a spreadsheet and everything. I know, I'm a nerd.
I know that feeling!
:!: I know we all want what's best for our Zs, it's only natural, but I'd be a little cautious of supermarket fuels... urban myths maybe, but I know someone (I know everyone does!) who's engine troubles were attributed to supermarket fuels. A Mazda I think. If things are tight I used to run 95RON from the big boys... before the sums. Probably all nonsense.
Either way, sounds like you're a new owner, enjoy... had mine over 3 years and if I'm having a really bad day nothing's more certain to return a smile to my face!
:!: I know we all want what's best for our Zs, it's only natural, but I'd be a little cautious of supermarket fuels... urban myths maybe, but I know someone (I know everyone does!) who's engine troubles were attributed to supermarket fuels. A Mazda I think. If things are tight I used to run 95RON from the big boys... before the sums. Probably all nonsense.
Either way, sounds like you're a new owner, enjoy... had mine over 3 years and if I'm having a really bad day nothing's more certain to return a smile to my face!
lacroupade
Lifer
From a lot of reading and research on the subject (including the use of acetone in diesel and even petrol), the concensus seems to be twofold: (i) theres only any point in using 98 RON if the engine is built to take advantage of it, and a lot are not these days, and (ii) the (to be frank) as yet unproven urban myth about supermarket fuel.
Personally I don't subscribe to the latter myself - its a bit like the ban on using mobile phones on petrol forecourts, just try and find a proven incident where one has EVER caused a fire. The petrol all comes from the same refineries, and as I understand it from oil industry scientists (of whom I know two) its all down to additives stuck into the tanker. So logic tells me there shouldn't be a problem - doesn't prove it entirely I know, but its good enough for me and I've used supermarket fuels for ever without problem and I don't know anyone who's had one....a problem that is, not a supermarket
having said that, Mr Zed gets higher grade BP or Shell usually and the latter seems to do best I have to say 8)
PS If anyone has GOOD intelligence on supermarket fuels causing damage I'd be interested to see it please - and thats not a challenge BTW!
Personally I don't subscribe to the latter myself - its a bit like the ban on using mobile phones on petrol forecourts, just try and find a proven incident where one has EVER caused a fire. The petrol all comes from the same refineries, and as I understand it from oil industry scientists (of whom I know two) its all down to additives stuck into the tanker. So logic tells me there shouldn't be a problem - doesn't prove it entirely I know, but its good enough for me and I've used supermarket fuels for ever without problem and I don't know anyone who's had one....a problem that is, not a supermarket
having said that, Mr Zed gets higher grade BP or Shell usually and the latter seems to do best I have to say 8)
PS If anyone has GOOD intelligence on supermarket fuels causing damage I'd be interested to see it please - and thats not a challenge BTW!
PawnSacrifice said:I know that feeling!
:!: I know we all want what's best for our Zs, it's only natural, but I'd be a little cautious of supermarket fuels... urban myths maybe, but I know someone (I know everyone does!) who's engine troubles were attributed to supermarket fuels. A Mazda I think. If things are tight I used to run 95RON from the big boys... before the sums. Probably all nonsense.
Either way, sounds like you're a new owner, enjoy... had mine over 3 years and if I'm having a really bad day nothing's more certain to return a smile to my face!
I know the smile to my face feeling when I start the car! One of the biggest reason I bought the car as well
I've used supermarket fuel in my Mini since day 1 and had no prob. Ok, I know its a completely different class. I cant believe supermarkets will risk being sued to high heaven by diluting their fuel to below the standard they advertise. Esp when it can be easily tested.
AJZ4London
Member
since switching to premium I have gone from 23/24mpg to 27/28. I probably don't drive as aggressively as I used to...but still!
This is similar to what someone told me... reader comment on an article about Vauxhall cars losing power when driving...
"... The last time this happened which was only 2 weeks ago the garage did mention it may be due to the supermarket fuel that we put into the car..."
Pretty sure the person I heard from was told it by a Mazda dealer.
GOOD intelligence - a franchised dealer faced with warranty work?
Mr Whippy provided the indisputable truth, these fuels have to conform to an industry standards.
RX-78, as you are experimenting, if you do try high octane Shell / BP etc as well, seeing how that compares to Tesco! Does it pay for itself?
I'll go stand in the corner and stop straying from the OP with hearsay... Apologies, Newbie.
"... The last time this happened which was only 2 weeks ago the garage did mention it may be due to the supermarket fuel that we put into the car..."
Pretty sure the person I heard from was told it by a Mazda dealer.
GOOD intelligence - a franchised dealer faced with warranty work?
Mr Whippy provided the indisputable truth, these fuels have to conform to an industry standards.
RX-78, as you are experimenting, if you do try high octane Shell / BP etc as well, seeing how that compares to Tesco! Does it pay for itself?
I'll go stand in the corner and stop straying from the OP with hearsay... Apologies, Newbie.
lacroupade said:The petrol all comes from the same refineries, and as I understand it from oil industry scientists (of whom I know two) its all down to additives stuck into the tanker. So logic tells me there shouldn't be a problem - doesn't prove it entirely I know, but its good enough for me and I've used supermarket fuels for ever without problem and I don't know anyone who's had one....a problem that is, not a supermarket
PS If anyone has GOOD intelligence on supermarket fuels causing damage I'd be interested to see it please - and thats not a challenge BTW!
Short memory? - Tecso and Morrisons fuel caused £10m of damage to cars in 2007 with silicone contamination damage and required the draining and refilling of 2 hundred of supermarket tanks. While not the refinery it's intersting that the supermarkets used a 'cheap' intermediary and no BP, Shell, etc. were affected.
http://en.wikipedia.org/wiki/Petrol_contamination
Still that said as per op question I've used Tesco 99 for all time on the Zed and can fee a benefit in response and MPG. My X5 that has the same engine but mapped to run differently and will almost take paraffin gets cheap 95
lacroupade
Lifer
cj10jeeper said:lacroupade said:The petrol all comes from the same refineries, and as I understand it from oil industry scientists (of whom I know two) its all down to additives stuck into the tanker. So logic tells me there shouldn't be a problem - doesn't prove it entirely I know, but its good enough for me and I've used supermarket fuels for ever without problem and I don't know anyone who's had one....a problem that is, not a supermarket
PS If anyone has GOOD intelligence on supermarket fuels causing damage I'd be interested to see it please - and thats not a challenge BTW!
Short memory? - Tecso and Morrisons fuel caused £10m of damage to cars in 2007 with silicone contamination damage and required the draining and refilling of 2 hundred of supermarket tanks. While not the refinery it's intersting that the supermarkets used a 'cheap' intermediary and no BP, Shell, etc. were affected.
http://en.wikipedia.org/wiki/Petrol_contamination
Still that said as per op question I've used Tesco 99 for all time on the Zed and can fee a benefit in response and MPG. My X5 that has the same engine but mapped to run differently and will almost take paraffin gets cheap 95
LOL, clearly I was having a senior moment there CJ!
ldman: But to be fair, that was in issue over cross-contamination really, as opposed to a generic "all supermarket petrol is crap", but I guess the warning on the packet should be the same....
Having recently moved back to Germany I`ve noticed that Shell over here are selling "Shell Racing Unleaded"! Have`nt tried the stuff yet as I`m only now on reserve but will get some later this week. It`s bloody expensive though at around 1.46 euros a litre-gulp! I`m not 100% on what the Ron rating is but I`m sure that it is 101 which would make sense as to it`s steep price.
