Supermarket Fuel, Facts Please

[DoubleD]

Thesprucegoose said:

Look at people reporting mpgs, they always report what they think which is usually incorrect. The problem is that when a premium product has so little difference from standard people will subconscious think it is better therefore lie to themselves about it.

My calculator must have lied to me then.

[Black_S3]

Standard 95 is usually made to identical BS specs. The marketing lot at bp and shell will attept to tell you their stuff saves you fuel. This of course is bullst as only a higher calorific value could achieve that.

Super is usually identical base fuel (same bs standard) with octane boosted by ethanol again to a BS standard. Only way they really differ is RON value.

Sticking super in the majority of cars makes the % difference you would expect from the difference in the Ron value - if the car can adapt to it. Some stuff does require it to run correctly - mainly high end stuff and remapped cars where the injectors over their limit with 95/ it will run lean & cause detonation.

[Deep Thought]

FK said:

Afternoon,

It's a Mk1 2.0 Petrol Ghia. I would imagine it's not set up for 98 RON or above, and I wasn't expecting the car to suddenly eat 911s and R8s for breakfast. But a few posts on here, and other research I have done, has at least implied that some super unleaded fuels may have additives that keep the engine in a slightly cleaner state.

For the moment it's getting Shell 95 as it's currently priced the same as my local Sains and Tesco, and it's actually on my way to work. Plus I have seen no change in mpg, still getting around 35 or so. But I have nothing against supermarket fuels at all

It was more from the wasting money perspective.

I'd be going for the premium brand 95 RON fuels. You're really paying a lot extra (usually) for 98 / 99 RON that your car doesnt need.

I use Millers Fuel Additive which contains cleaning agents, an octane boost, etc and works out at 2.5p per litre of fuel. It would mean you could use the cheapest fuel but have the consistency of the fuel additives / octane boost.

Comes highly rated and has been on the market a long time

https://www.halfords.com/motoring/engine-oils-flui...

Edited by Deep Thought on Saturday 15th December 15:40

[jagnet]

Black_S3 said:

This of course is bullst as only a higher calorific value could achieve that.

Friction modifiers added to the fuel will also see gains in mpg.

[Black_S3]

jagnet said:

Black_S3 said:

This of course is bullst as only a higher calorific value could achieve that.

Friction modifiers added to the fuel will also see gains in mpg.

Engines are lubricated by oil which I agree the top end ones can have a huge effect on fuel consumption.

Suggesting that a friction reduction additive in fuel, in such dilute quantities, that Is only in a lubricating state for the tiny % of the whole process before it is burnt reduces fuel consumption is bullst.

[jagnet]

Black_S3 said:

Suggesting that a friction reduction additive in fuel, in such dilute quantities, that Is only in a lubricating state for the tiny % of the whole process before it is burnt reduces fuel consumption is bullst.

From page 10 of this thread:

jagnet said:

Hayden et al 2001 said:

The benefit of the gasoline friction modifier fuel additive was generally found at the higher oil temperature conditions. The fuel economy change was immediately measurable and further gains were seen as the friction modifier fuel additive accumulated in the engine oil and reduced friction in oil-wetted parts of the engine. The use of friction modifiers in engine oil formulations did not negate the fuel additive benefit. This program has shown that using the fuel to supply a friction modifier is a practical method to improve vehicle fuel economy.

Hayden, T., Ropes, C., and Rawdon, M., "The Performance of a Gasoline Friction Modifier Fuel Additive," SAE Technical Paper 2001-01-1961, 2001, https://doi.org/10.4271/2001-01-1961.

Given that the piston rings account for ~50% of the frictional losses in an engine, friction reducers added via the fuel are well placed to reduce these losses. The study above found average instantaneous fuel economy improvements of 2% and predicted long term average fuel economy benefits of 3%.

[Black_S3]

You are free to buy in to what you want. The fact of is the time before combustion is so small and would not cover much of bore. That even mentions the stuff only has a benefit at higher oil temperatures, highlighting the point friction is reduced by oil and a true benefit comes from the likes of an ester synthetic oil that will remain stable & some of the new nano tech addatives in high end oils - that I buy into.

I’ll accept shell will have proven a gain or they wouldn’t be able to call their stuff fuel-save, however if your car gets 31.6mpg with Tesco 95 you will get 31.6 with shells 95 extra special fuel save. Still bullst for me.

Edited by Black_S3 on Saturday 15th December 16:22

[FK]

Deep Thought said:

FK said:

Afternoon,

It's a Mk1 2.0 Petrol Ghia. I would imagine it's not set up for 98 RON or above, and I wasn't expecting the car to suddenly eat 911s and R8s for breakfast. But a few posts on here, and other research I have done, has at least implied that some super unleaded fuels may have additives that keep the engine in a slightly cleaner state.

For the moment it's getting Shell 95 as it's currently priced the same as my local Sains and Tesco, and it's actually on my way to work. Plus I have seen no change in mpg, still getting around 35 or so. But I have nothing against supermarket fuels at all

It was more from the wasting money perspective.

I'd be going for the premium brand 95 RON fuels. You're really paying a lot extra (usually) for 98 / 99 RON that your car doesnt need.

I use Millers Fuel Additive which contains cleaning agents, an octane boost, etc and works out at 2.5p per litre of fuel. It would mean you could use the cheapest fuel but have the consistency of the fuel additives / octane boost.

Comes highly rated and has been on the market a long time

https://www.halfords.com/motoring/engine-oils-flui...

Edited by Deep Thought on Saturday 15th December 15:40

Thanks for the link.

Yes this is true, super serves virtually no benefit in my motor. I'm just glad that most of the time I was filling up with Tesco super (which where I live tends to be priced the same as everyone else's 'normal 95'). So not as much money wasted as I could have done

You live and learn. I used to think I knew a thing or two about cars before I joined!

[gizlaroc]

FK said:

Afternoon,

It's a Mk1 2.0 Petrol Ghia. I would imagine it's not set up for 98 RON or above, and I wasn't expecting the car to suddenly eat 911s and R8s for breakfast. But a few posts on here, and other research I have done, has at least implied that some super unleaded fuels may have additives that keep the engine in a slightly cleaner state.

For the moment it's getting Shell 95 as it's currently priced the same as my local Sains and Tesco, and it's actually on my way to work. Plus I have seen no change in mpg, still getting around 35 or so. But I have nothing against supermarket fuels at all

I meant that you will only see a change in mpg if your car is set up to take 98 and advance the timing.

My Merc used to throw an emissions error if I used Sainsburys petrol.
One tank of Shell and it would go out.

[jagnet]

Black_S3 said:

You are free to buy in to what you want. The fact of is the time before combustion is so small and would not cover much of bore.

I’ll accept shell will have proven a gain or they wouldn’t be able to call their stuff fuel-save, however if your car gets 31.6mpg with Tesco 95 you will get 31.6 with shells 95 extra special fuel save. Still bullst for me.

Whilst it's too small a gain to reliably measure whilst driving with all the variability that entails (and likely why Shell had to stop with the "FuelSave" marketing angle), friction modifiers in fuel can affect fuel consumption. They aren't burnt off in the combustion event and they do get past the piston rings leading to a build up in the oil, hence the longer term gains found in the SAE paper.

Friction modifiers in the oil can give a greater improvement in mpg and one that is much more noticeable when filling up at the pump, but as a fuel additive they're still of benefit, just as a 20W oil is more fuel efficient than a 30W one. A similarly slight benefit for sure that you'll struggle to measure differences between in normal driving conditions, but a benefit all the same.

[Black_S3]

gizlaroc said:

I meant that you will only see a change in mpg if your car is set up to take 98 and advance the timing.

My Merc used to throw an emissions error if I used Sainsburys petrol.
One tank of Shell and it would go out.

I used to experience similar with a remapped car..... it just did not like BP Ultimate or Sainsbury’s super.... same car 10 years on no longer has a problem with the stuff so I guess they changed it.

[FK]

gizlaroc said:

FK said:

Afternoon,

It's a Mk1 2.0 Petrol Ghia. I would imagine it's not set up for 98 RON or above, and I wasn't expecting the car to suddenly eat 911s and R8s for breakfast. But a few posts on here, and other research I have done, has at least implied that some super unleaded fuels may have additives that keep the engine in a slightly cleaner state.

For the moment it's getting Shell 95 as it's currently priced the same as my local Sains and Tesco, and it's actually on my way to work. Plus I have seen no change in mpg, still getting around 35 or so. But I have nothing against supermarket fuels at all

I meant that you will only see a change in mpg if your car is set up to take 98 and advance the timing.

My Merc used to throw an emissions error if I used Sainsburys petrol.
One tank of Shell and it would go out.

Makes sense, this would go some way to explaining why my mpg did not change at all when I made the switch back to 95! Performance didn't change much either incidentally, nor did I expect it to.

That's interesting about the Merc; my dad has a c320 and I'm pretty sure he just chucks in whatever is cheapest. So I will see if there are any odd issues that he may be experiencing.

[Black_S3]

jagnet said:

Whilst it's too small a gain to reliably measure whilst driving with all the variability that entails (and likely why Shell had to stop with the "FuelSave" marketing angle), friction modifiers in fuel can affect fuel consumption. They aren't burnt off in the combustion event and they do get past the piston rings leading to a build up in the oil, hence the longer term gains found in the SAE paper.

That makes absolute sense on how they got away with the ‘fuel save’ claim....

The truth is, friction modifiers should be added to the oil not to the fuel.

[Deep Thought]

FK said:

Thanks for the link.

Yes this is true, super serves virtually no benefit in my motor. I'm just glad that most of the time I was filling up with Tesco super (which where I live tends to be priced the same as everyone else's 'normal 95'). So not as much money wasted as I could have done

You live and learn. I used to think I knew a thing or two about cars before I joined!

I think you're doing the right thing using premium fuels where possible to get the additives. Just no need to be spending the extra for premium and the higher RON.

That Millers is good stuff and works out a lot cheaper. I just stick it in when i get home after filling the car.

[FK]

Deep Thought said:

FK said:

Thanks for the link.

Yes this is true, super serves virtually no benefit in my motor. I'm just glad that most of the time I was filling up with Tesco super (which where I live tends to be priced the same as everyone else's 'normal 95'). So not as much money wasted as I could have done

You live and learn. I used to think I knew a thing or two about cars before I joined!

I think you're doing the right thing using premium fuels where possible to get the additives. Just no need to be spending the extra for premium and the higher RON.

That Millers is good stuff and works out a lot cheaper. I just stick it in when i get home after filling the car.

Yes, until recently (when I actually bothered to do a bit of research) I had assumed that it was only the higher RON fuels that had the cleaning additives. I found out since that this is not at all the case!

Will check out this millers stuff when I'm next near a halfords. Or I might see if eurocarparts has it as well, since they seem to be the automotive equivalent of DFS

[Deep Thought]

FK said:

Yes, until recently (when I actually bothered to do a bit of research) I had assumed that it was only the higher RON fuels that had the cleaning additives. I found out since that this is not at all the case!

Will check out this millers stuff when I'm next near a halfords. Or I might see if eurocarparts has it as well, since they seem to be the automotive equivalent of DFS

You can get it in loads of places - i normally get mine delivered from ebay. Amazon have it too, but its expensive on there at the minute. Halfords prices seem about the cheapest at the min.

[DoubleD]

Didnt 5th gear test fuel additives like millers and found that the reduced power?

[Deep Thought]

DoubleD said:

Didnt 5th gear test fuel additives like millers and found that the reduced power?

They were testing power boosters. They didnt test Millers.

I dont use Millers for any perceived power increase, its for the cleaning agents in it.