Type of fuel

[EnzoMC]

interesting thread, I'm sadly one that mostly use Shell or BP but its for the cleaning / detergents that these have or is this also misleading.

 

[CatmanV2]

some good points there from the people in the know, but supermarket stuff just makes me nervous for any high performance motors, might be unfounded but just how I feel about it, for the extra pennies i'd rather use V Power

The power of marketing!

C

 

[Wanderer]

Can we have some titties on this thread, I switched off ages ago? Who’s this Ron bloke? Jeremies?

 

[cheshiremaserati]

some good points there from the people in the know, but supermarket stuff just makes me nervous for any high performance motors, might be unfounded but just how I feel about it, for the extra pennies i'd rather use V Power

That is entirely your choice. There is a big element of marketing that drive people to more expensive branded fuels. Supermarkets buy wholesale fuel by tender. Who supplies that fuel on tender? Shell, BP, Esso etc. at the refinery.

 

[cheshiremaserati]

interesting thread, I'm sadly one that mostly use Shell or BP but its for the cleaning / detergents that these have or is this also misleading.

No the additives and detergents are real. Over several tankfulls they can make a difference to state of injector nozzles etc. But so can adding Redex at £2 for two tankfulls when on offer or £4 without an offer. All this stuff about fuel comes up with the Porsche forum - some suffering severe paranoia that there Porsche is gonna blow up cos they filled up with Sainsbury Super Unleaded instead of Shell V-Power (and Sainsbury Super Unleaded is only 97 RON not 99 as advised by Porsche).

 

[lifes2short]

That is entirely your choice. There is a big element of marketing that drive people to more expensive branded fuels. Supermarkets buy wholesale fuel by tender. Who supplies that fuel on tender? Shell, BP, Esso etc. at the refinery.

agreed its probably all the same, but I just sleep better knowing I have V Power in my tanks

 

[lifes2short]

The power of marketing!

C

I'm the marketing guys dreams

 

[Wanderer]

Is the fear not from the supermarket petrol causing engines to seize scare and decade or so back? What happened there - was it unfounded or was it naff petrol?

 

[lifes2short]

Can we have some titties on this thread

sorry, titties reserved for the B thread

 

[CatmanV2]

I'm the marketing guys dreams

Clearly

C

 

[lifes2short]

Clearly

C

yup, I almost bought an air guitar once

 

[Ryandoc]

Folks, all fuel, supermarket or premium, is the exact same source and only the additives differ, the additive are added at the loading nozzle at the tanker compartment. 100% fact.

I use to work on Stanlow road terminal when it was shell, I managed the loading system, carried spare BOL loading cards around with me etc etc.

I’ll put absolutely anything into my cars and have, however in the GTS I predominantly use V power. But would think nothing of banging Asda’s boggo standard stuff in if I needed to.

To add a point shell have not manufactured their own fuels in this country for a good few years now since they sold stanlow, someone else makes it and adds shell’s Addictive package for them.

 

[davy83]

That may well be true, i suspect there is a core timing map which never changes and the adjustments that are made are all within a range to prevent the ECU from getting too carried away, I also suspect there is a "current map" which is separate from the core map and it is this that the ECU messses around with. Without getting some core information from the engineers that wrote the code in the ECU I suspect we will never really know!!

You may be correct however my understanding is the map provides a series of ranges and is not in fact updated. But what do I know
C

 

[CatmanV2]

That may well be true, i suspect there is a core timing map which never changes and the adjustments that are made are all within a range to prevent the ECU from getting too carried away,

I think you've just described the whole map......

I'm not at all convinced about the other one. The timing pretty much needs to be adjusted after every power stroke, before the next one. I just don't see the point of long term adjustment. What if you change fuel every tank for a different octane. You're never going to catch up.

Gearboxes and transmissions, OTOH

But like I say, I know sod all

C

 

[skyestuart]

These fuel threads appear on car forums with a similar regularity as do ones on Kennedy's assassination, alien abductions and the chances of Boris Johnson ever becoming PM. Sadly it seems only the last one appears to be reality.

 

[FIFTY]

I find it interesting/amusing how the thread has gone from - yes super makes a noticeable difference on turbo cars but probably only a 2-3% difference on N/A cars

To

No it's a marketing scam don't buy it you fools

 

[davy83]

I think you've just described the whole map......

I'm not at all convinced about the other one. The timing pretty much needs to be adjusted after every power stroke, before the next one. I just don't see the point of long term adjustment. What if you change fuel every tank for a different octane. You're never going to catch up.

Gearboxes and transmissions, OTOH

But like I say, I know sod all

C

The key to this is pinking or knock, its bad for the engine, if left unchecked over long periods. The knock sensors detect it when it happens and the ECU will retard the ignition on the next cycle, but by that time its al;ready happened. The long term map tries to work out the safest and most advanced ignition timing that does not create knock in the first place. When the ECU is electronically deciding when to spark the next combustion it needs to aim for the optimum setting that will not create knock. It uses the knock sensors to determine when its gone too far and, if knock is detected it retards the ignition immediately but also makes a slight adjustment to the long term map to try and avoid that condition in future, and will gradually adjust the long term map until its no longer detects knock in that engine condition. That's why when the knock sensors fail the engine goes way off tune because all the timing gets set to safe settings.

So the reason there is a long term map is that it needs this to get the optimum advance settings in advance of needing them. The real time blow by blow adjustment is used to stop any detected knocking, and also to learn and update the map. This learning of the map takes several hundred miles to my knowledge and also I think dealers are able to reset this mapping function to get the ECU to start with a clean sheet, after repairs etc.

So while I freely admit that (even given all this wonderful self learning going on) the feeling of the car will be much the same with either low grade or high grade fuel, It does take a little time for the car to adapt to a different grade of fuel so if you are trying different fuels be patient!

I would be interested if anyone knows how to reset the 3200 ignition learning map, as this would be a useful thing to know, I seem to think its been mentioned on here somewhere.

I will crawl back into my cage now.

 

[Zep]

A few facts need to be realised.

1. Octane rating indicates the ability of the fuel to resist knocking,or,pre-ignition,under high compression. The higher the rating the less likely pre-ignition will occur under most driving conditions.
2. There is absolutely no relation between the octane rating & the power an engine will attain. Power is dependant on the chemistry of the fuel,more specifically it's calorific value.
3. Unless the engine is both constructed & tuned to take advantage of high octane fuel it is wasted. In general terms high octane fuel is used for high compression engines.
4. There are two ways of rating octane ratios. The Research method,abbreviated as RON,is the common way of rating a fuel. RON indicates the ability of the fuel to resist knocking under low engine revolutions. The Motor Octane Rating measures the fuel's ability to resist knocking under high engine revolutions. Both Ron & Mon are measured on all gasoline fuels.
5. You are wasting your money on Avgas which is designed for use in piston engined aircraft which run at low & constant revolutions. It can be used in cars but why bother unless you are stealing it from your employer ?

It was used in the past for old engines which required lead fuel additive.
6. It's probably wise to accept the fuel recommendations of the car's manufacturer but the reality is that regular gasolione usually suffices since the ECU will adjust the timing via the knock sensors. The power developed by the engine will be the same. After all,road cars are tuned for easy driveability,not performance, so discussion around the relative merits of different brands of fuel is futile. However,you have a more important consideration on fuel branding. What you buy at say,a Shell station is not always Shell fuel. Fuel at a station is often bought from another refinery due to distribution difficulties or cost considerations and the mix is further complicated since a lot of fuel is imported from overseas by all companies to augment their supply chain. So what you buy as Shell may have come from a Mobil refinery mixed with imported fuel from China. And,you'll never know the difference !
When you remove all the gimmickry & sales bulls*it from fuels there's little justification for not buying the fuel closest to home at the lowest price,the car will cope just the same.

All entirely valid, but regarding the different methodology for RON and MON.

The RON is measured on a variable compression test engine with fixed ignition timing operating at 600 rpm.

MON is measured on a slightly different variable compression engine running at 900 rpm, with preheated fuel and variable ignition timing which creates more stress.

In any event, a fuel with a higher RON should also have a higher MON, because the driver of the test results is the same, but the chemical makeup of the fuel will skew the correlation.

As stated above, it is a fact that if your engine runs with more ignition advance it will produce more torque for the same amount of fuel. It’s ability to do this is governed by the fuel quality (RON and MON) but to put it simplistically, you can either go a bit faster or save some fuel, but you can’t, generally, do both.

 

[CatmanV2]

You cannae change the laws of physics!
C

 

[pj_sibley]

I've always stuck with Shell V-Power 99RON in my performance cars, more force of habit than anything else. Only really makes a difference in a turbocharged car in my experience but there's no doubt its good quality fuel.