Is Texaco premium not really "premium"?

[X100]

Until a few days ago, I have only ever used Shell V-Power, at 98 octane, in my RC F.

Last week, I filled up with Texaco's premium fuel, only to discover that it is actually 97 octane.

Should I be concerned?

I typically accelerate hard perhaps 3-4 times on a 50-mile trip, usually where the limit is 70mph, so for just a few seconds.  Otherwise, I am in traffic, like everyone else.

Do I need to lay off the hard acceleration until I can top up a decent amount with 98 octane?

[talaipwros]

There is no need using "Premium" fuel in UK

[Jgtcracer]

5 minutes ago, X100 said:

Until a few days ago, I have only ever used Shell V-Power, at 98 octane, in my RC F.

Last week, I filled up with Texaco's premium fuel, only to discover that it is actually 97 octane.

Should I be concerned?

I typically accelerate hard perhaps 3-4 times on a 50-mile trip, usually where the limit is 70mph, so for just a few seconds.  Otherwise, I am in traffic, like everyone else.

Do I need to lay off the hard acceleration until I can top up a decent amount with 98 octane?

It’ll be fine, don’t worry about it.  The car will run on 95 to be honest, though premium is always going to be better.  
 

I think Vpower is 99 octane

[talaipwros]

1 minute ago, Jgtcracer said:

It’ll be fine, don’t worry about it.  The car will run on 95 to be honest, though premium is always going to be better.  
 

I think Vpower is 99 octane

Actually, the car will run in 91 ( 91 is Premium in the US)

[Rensin55]

US 91AKI premium is roughly equivalent to UK 97RON. 

[Huwge]

Esso is always an option. Their premium fuel has no ethanol content (though the pump will still say E5)

[Las Palmas]

11 minutes ago, Jgtcracer said:

It’ll be fine, don’t worry about it.  The car will run on 95 to be honest, though premium is always going to be better.  
 

I think Vpower is 99 octane

Here V-Power is listed as 98.

Do not believe there is any noticeable difference in the way the cars drive with 95 - 98

[hockeyedwards]

2 minutes ago, Huwge said:

Esso is always an option. Their premium fuel has no ethanol content (though the pump will still say E5)

I think it is on Esso website why they have to put the E5 sticker, 'technically' it means 'can contain up to 5%', so despite being 0, they still gotta put the E5 on it.

I ran the GS on V-Power and then switched to Esso once I realised it has no ethanol 🙂

[talaipwros]

6 minutes ago, Rensin55 said:

US 91AKI premium is roughly equivalent to UK 97RON. 

nope, to UK95

 

https://aircooledbug.co.uk/usa-versus-uk-fuel-octane/

 

 

[Jgtcracer]

24 minutes ago, Las Palmas said:

Here V-Power is listed as 98.

Do not believe there is any noticeable difference in the way the cars drive with 95 - 98

That’s interesting, Shell UK site rates it at 99ron. Perhaps it’s different by country.

https://support.shell.com/hc/en-gb/articles/115002792532-What-is-Octane-

[Rob RCF]

1 hour ago, X100 said:

Until a few days ago, I have only ever used Shell V-Power, at 98 octane, in my RC F.

Last week, I filled up with Texaco's premium fuel, only to discover that it is actually 97 octane.

Should I be concerned?

I typically accelerate hard perhaps 3-4 times on a 50-mile trip, usually where the limit is 70mph, so for just a few seconds.  Otherwise, I am in traffic, like everyone else.

Do I need to lay off the hard acceleration until I can top up a decent amount with 98 octane?

If you read the manual you'll see it recommends 98 RON, but it also says underneath that if it's not available 95 RON can be used with no harm to the engine. You should still be able to drive it hard. You just might make a bit less power.

You can read up about KCLV if you want to know more about the engine's knock correction and how it learns over time.

[X100]

That's great - Thanks Rob!

[X100]

Thanks to everyone else for your comments too.  Much appreciated!

[ubersonic]

9 hours ago, X100 said:

Last week, I filled up with Texaco's premium fuel, only to discover that it is actually 97 octane.

Texaco (and ESSO) super unleaded can be 97 or 99 depending on the part of the country the fuelling station is in (it tends to be opposing areas, so if you can get one you usually can't get the other).

[bigglesfllesundone]

On Esso website it stated that:

Esso Synergy Supreme+ is ethanol free (except in North of England, North Wales, Scotland, Devon and Cornwall) 

I contacted Esso who sent a spreadsheet of all petrol stations where Synergy Supreme+ is stocked, (attached.)

As Ethanol produces less energy when burnt than petrol, E10 produces about 3.4% less energy than 100% petrol.

Sites supplied from Esso terminals.xlsxSynergy Supreme+ is 196.9p, locally, 7p more than Esso E10 (about 3.4%) this makes its use cost neutral.

[DamianLEX]

A quick calculation tells me then:

477HP * 0.034 ethanol = 16HP and that's if fuel is the same 95/97/98/99.

But what if we take 97-99 octanes with no ethanol comparing to 95 with ethanol? 

I bet easy 20-30HP in total.

Just to think about some people paying stupid money to upgrade 5-10HP by changing exhaust, remap etc

Here 60 litres * 1.99(98) comparing to 60 litres * 1.91 (95)= £4.8 on each fuel tank (average).

For me is a no-brainer. Standard  95 is so expensive that soon if we have 95 for £9.91 and 98 for £9.99 are you still going to save this few pence on fuel just because you can run on it?

 

 

[ColinBarber]

On 6/26/2022 at 1:24 PM, talaipwros said:

Actually, the car will run in 91 ( 91 is Premium in the US)

It won't run on 91 RON, but that isn't available in the UK anyway. 95RON is the lowest suggested fuel on the F engine. 

[Jgtcracer]

2 hours ago, DamianLEX said:

A quick calculation tells me then:

477HP * 0.034 ethanol = 16HP and that's if fuel is the same 95/97/98/99.

But what if we take 97-99 octanes with no ethanol comparing to 95 with ethanol? 

I bet easy 20-30HP in total.

Just to think about some people paying stupid money to upgrade 5-10HP by changing exhaust, remap etc

Here 60 litres * 1.99(98) comparing to 60 litres * 1.91 (95)= £4.8 on each fuel tank (average).

For me is a no-brainer. Standard  95 is so expensive that soon if we have 95 for £9.91 and 98 for £9.99 are you still going to save this few pence on fuel just because you can run on it?

 

 

Sorry, I’m struggling to follow.  Are you saying that 98RON without ethanol can make 20-30bhp more that 95RON with 10% ethanol?  
 

that’s quite a difference!

[ColinBarber]

1 hour ago, Jgtcracer said:

Sorry, I’m struggling to follow.  Are you saying that 98RON without ethanol can make 20-30bhp more that 95RON with 10% ethanol?  
 

that’s quite a difference!

The quote previous stated a 3.4% drop in energy, and 3.4% of 477 is 16.

At max throttle/power that is probably accurate. However it isn’t quite that simple in normal running as whilst the energy is less, the fuelling system will add more to compensate so you might not see such a drop in power - but you will see a drop in economy. 

[Twellsie]

just give us E85 !

[ubersonic]

23 hours ago, DamianLEX said:

A quick calculation tells me then:

477HP * 0.034 ethanol = 16HP and that's if fuel is the same 95/97/98/99.

But what if we take 97-99 octanes with no ethanol comparing to 95 with ethanol? 

I bet easy 20-30HP in total.

I could be wrong here as I'm pretty tired but I think this may be a misunderstanding of what is meant by ethanol producing less energy.

Ethanol has a lower calorific value than petroleum which essentially means that (I.E) Premium 95RON E10 will provide lower MPG than the the E5 variant of it did.

Power should not be affected as if a car makes 417hp on 95RON fuel (using the ISF as an example), then it doesn't matter what ethanol content the fuel has.

[Winston]

Just personally I have had a wide range of cars and I have never noticed any difference in power using the lower or higher rated fuels available at the pumps

[Jgtcracer]

3 hours ago, Winston said:

Just personally I have had a wide range of cars and I have never noticed any difference in power using the lower or higher rated fuels available at the pumps

Neither have I, though I probably wouldn’t.  I’m pretty sure cars today have the ability to adjust parameters to maintain performance.  I’ll usually use Vpower intermittently for the cleaning properties it provides.

 

[X100]

Some really helpful comments here.  Thank you!

I shall most likely go back to Shell 98 octane next time (for its cleaning ability) although I could be tempted by ethanol-free Esso premium ...

[DamianLEX]

So today I had only 10 miles left to go in my RCF after gentle driving. Nearly empty.

I put as much petrol in as I possibly could (see pictures). I will not believe that we have more than 60 litres capacity in RCF until I see one screenshot with over 60 litres on the meter.