Finding super unleaded petrol stations

Nasher · 29 Jun 2018 at 12:17

sideways14a said:
Yeah if your really worried then a bottle of octane boost could be used but the uk 350 doesnt really need it, it wont go boom unless its not in the greatest of health in the first place.

I once used BP ultimate, the most expensive of the so called super unleaded fuels. It was awful, lit the knock gauge up list a Christmas tree.
It was pants petrol.... tescos own 99 is actually quite good, as is shells 99 of course.

Yea I had a bad experience with BP's as well. Lit an engine warning light up on a celica I had years ago and sent it in to limp mode :/

Gixer · 29 Jun 2018 at 12:25

Looks like I'll need to plan my fuel filling!

Flibster · 29 Jun 2018 at 14:15

jpaul said:
yes you are right - it is 97

[the new mazda 6 turbo - I like their design&engines - had caught my eye 227 vs 250bhp with super https://youtu.be/BzCPaTHg0-I?t=84 ]

Is that engine actually coming to the uk?

jpaul · 29 Jun 2018 at 15:13

Flibster said:
Is that engine actually coming to the uk?

maybe not

don't they want more of the BMW 3 market ? imports too expensive ?

Upgraded “six”, first presented last fall in America, has now reached the Old world: the local premiere took place at the Geneva motor show. Almost all new clothes crossed with “American” and spread as a sedan and wagon. The only loss is the 2.5 turbo (253 HP): potential demand for such versions in Europe is low. But local buyers will be offered an upgraded diesel Skyactiv-D.

Frozennova · 29 Jun 2018 at 15:15

Nasher said:
The higher RON just increases the combustion temperature. That will only benefit engines with a high compression ratio, beyond the point where 95 would detonate before the spark (just from being compressed). Which is usually high revving NA ones.

Octane rating doesn't affect combustion temperature, it's a fuels ability to resist detonation.

There's far more than compression ratio that affects how likely an fuel is to detonate too.

Engines are also as a rule less likely to detonate at high RPM as cylinder pressure is generally lower than at peak torque for example

ahar · 29 Jun 2018 at 15:18

Ah nostalgia, I used to have to use 99RON in my scoob if I wanted to boot it as it had been been mapped to the edge using that to wring every last ounce of power from the engine. Used to keep a couple of bottles of the additive in the boot in case I got stuck (can't have a modified scoob without exploring its full capabilities

)

I seem to remember all the big tescos used to have 99RON so I just planned my fuelling around those and large shell garages as VPower was 99RON back then I think.

Akagi · 29 Jun 2018 at 15:19

Any Tesco or Shell will do 99, anywhere else will do 97 unless its a little indie establishment?

Cookeh · 29 Jun 2018 at 15:19

Haverfordwest has a Tesco that has super-unleaded, think the Morrisons offers it too. There are several Gulf/Texacos etc that have higher ron fuels (97 iirc) on the A40 from Fishguard to St Clears. There's an Esso on St Peters Road in Haverfordwest that has Synergy Supreme+. There's another Esso in St Clears (Tenby Road) that has the same fuel.

Gixer · 29 Jun 2018 at 15:21

Frozennova said:
Octane rating doesn't affect combustion temperature, it's a fuels ability to resist detonation.

There's far more than compression ratio that affects how likely an fuel is to detonate too.

Engines are also as a rule less likely to detonate at high RPM as cylinder pressure is generally lower than at peak torque for example

Exactly. It slows the burn. With a remap it's likely the ignition has been advanced so you need a slower burn to prevent the knock.

Gixer · 29 Jun 2018 at 15:34

Cookeh said:
Haverfordwest has a Tesco that has super-unleaded, think the Morrisons offers it too. There are several Gulf/Texacos etc that have higher ron fuels (97 iirc) on the A40 from Fishguard to St Clears. There's an Esso on St Peters Road in Haverfordwest that has Synergy Supreme+. There's another Esso in St Clears (Tenby Road) that has the same fuel.

Thanks. I'll keep an eye out whilst driving around but at least I have two dead certs and one is on my way so I'll top up then. I thought more would have premium fuels when I stayed down in Polperro, Cornwall, but most didn't have anything above 95ron.

sigma · 29 Jun 2018 at 16:53

Buy some octane booster?

Gixer · 29 Jun 2018 at 17:53

sigma said:
Buy some octane booster?

Could do but then I have to bother to work out how much to put in. I should for emergency purposes but I can't recall if octane booster goes off, as petrol does.

Frozennova · 29 Jun 2018 at 18:44

sigma said:
Buy some octane booster?

Gixer said:
Could do but then I have to bother to work out how much to put in. I should for emergency purposes but I can't recall if octane booster goes off, as petrol does.

1 Litre of toluene per 10 litres of 95RON would give you 97.6 RON fairly easily (Its the main component in a lot of octane boosters)

It's stoich ratio of 13.6:1 means the fuel mix will have a stoich ratio of 14.59 meaning less than 1% change to air-fuel ratiio compare to regular petrol

sigma · 29 Jun 2018 at 21:04

Frozennova said:
1 Litre of toluene per 10 litres of 95RON would give you 97.6 RON fairly easily (Its the main component in a lot of octane boosters)

It's stoich ratio of 13.6:1 means the fuel mix will have a stoich ratio of 14.59 meaning less than 1% change to air-fuel ratiio compare to regular petrol

Seems like a better option than going off route or having to plan where the stations are...

Deleted member 66701 · 29 Jun 2018 at 21:24

jpaul said:
Are there cars that do not benefit at all ?

Any car that:-

A: Hasn't been mapped on it
or
B: Doesn't use a knock sensor to adjust ignition timing

Simon · 29 Jun 2018 at 21:47

All cars benefit from the better additives in premium fuel

paradigm · 29 Jun 2018 at 22:06

Acme said:
Any Tesco or Shell will do 99, anywhere else will do 97 unless its a little indie establishment?

You would assume this, but the BP round the corner from me has nothing in the way of “super” fuels (in either diesel or unleaded form). The Sainsbury’s less than a mile away has super though.

Mel_P · 29 Jun 2018 at 22:49

Most Tesco forecourts sell "98" around S East?

Gixer · 30 Jun 2018 at 09:03

Frozennova said:
1 Litre of toluene per 10 litres of 95RON would give you 97.6 RON fairly easily (Its the main component in a lot of octane boosters)

It's stoich ratio of 13.6:1 means the fuel mix will have a stoich ratio of 14.59 meaning less than 1% change to air-fuel ratiio compare to regular petrol

Found 1ltr of toluene for £5. I have a 70ltr tank so filling at light would roughly be 50ltrs of fuel + 5ltrs of toluene (wouldn't quite be a full tank but close enough). That's an extra £25 and having to carry around a fair bit of toluene. I guess 1ltr for an emergency 10ltr top up would be OK. I'll just plan my journey accordingly on this holiday. It's not something I have to worry about in Southampton, there is premium fuel pretty much in every station.

Frozennova · 30 Jun 2018 at 09:52

Gixer said:
Found 1ltr of toluene for £5. I have a 70ltr tank so filling at light would roughly be 50ltrs of fuel + 5ltrs of toluene (wouldn't quite be a full tank but close enough). That's an extra £25 and having to carry around a fair bit of toluene. I guess 1ltr for an emergency 10ltr top up would be OK. I'll just plan my journey accordingly on this holiday. It's not something I have to worry about in Southampton, there is premium fuel pretty much in every station.

Darrant chemicals do 10 litres for £26 delivered.

Usually take 3 or 4 days to arrive, never had an issue with them in the best part of 500 litres of methanol I've had from them

http://darrantchemicals.co.uk/toluene?search=Toluene

Finding super unleaded petrol stations

Deleted member 66701

Deleted member 66701