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.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
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).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.
agreed its probably all the same, but I just sleep better knowing I have V Power in my tanksThat 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.
I'm the marketing guys dreamsThe power of marketing!
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Can we have some titties on this thread
yup, I almost bought an air guitar onceClearly
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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
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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,
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.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
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A few facts need to be realised.
It was used in the past for old engines which required lead fuel additive.
- 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.
- 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.
- 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.
- 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.
- 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 ?
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.