95 ron

[DOLBY]

Using 95 or any other lower octane fuel than recommended isn't a ploy by manufacturers, but simply saving your engine! Lower octane fuel won't burn as completely in an engine designed for higher performance. As a result, coke deposits will build up (especially on the spark plug cathodes) which will on a high load drive retain heat and glow red hot. This can pre-ignite the fuel and result in multiple pressure waves (which is also what produces the characteristic 'knock') within the engine, destroying the nitrogen layer between the burning fuel and piston crown that exists in normal conditions. With no nitrogen layer, the burning fuel hits the piston and blows a hole in it in moments.

This is all over a large distance (thousands of miles), but I still wouldn't recommend 95 unless you have no option or it is occasional. As for adding octane boosters, I don't know. It may negate the low burning temperatures (relatively) but I don't honestly know.

My 5 cents? Don't do it man!

Source: I work for Ford at their UK R&D facility

Well worth knowing this is....but you will be suprised the amount of people than run performance cars, including uber good ones like RS4's and M5's with this crappy fuel. Yeh yeh i know those cars are non turbo but still, my mind boggles at the thought.

 

[Sinbad]

Octane rating is not related to fuel quality.

 

[ozzymyster]

My lcr is running 95...probably has been since 2005 as better grade fuel is hard to come by....runs perfect and always has...haven't had it on rolling road so don't know what bhp it is...prob is down as its designed for 98 but I've no choice

 

[Nautilus]

Ran for the last few weeks on 98 RON fuel from a nearby station (just due to my daily route bypassing that station, not for cost, >100 RON fuel type Rompetrol Alto 101 was in British money only 0.53p more expensive per liter) and in 38-40°C days my LFR ran a little bit rough while under boost and A/C compressor on.

Switched today to >100 RON fuel (poured in almost empty tank, did not mix with anything else). Immediately the entire engine behavior changed, acceleration, boost, smoothness, even sound.

Strange, ain't it?..

The hotter the weather and higher the boost, the better octane needed.

The car never touched in 7 years and a half (from new) anything below 98 RON. But it ran best on just two types of fuels of the 10 brands over 98 RON available. One is >99 RON, the other >100 RON.

In current engine configuration, 95 RON in hot weather would be suicidal. I'd rather leave the car immobile and take the bus instead.

~Nautilus

 

[ozzymyster]

My lcr

Fine on 95 as I have no choice.

 

[DOLBY]

dude you need to wash that cap lol.

 

[mty12345]

lol, yh +1

 

[ozzymyster]

The sticker and the inside of the cap are the least of my worries...

 

[Nautilus]

A bunch of people in the USA and Australia happened to have access to a lab to measure the octane rating of the fuels (the test machine uses a one-cylinder engine with variable compression ratios, sensors and gauges) and took the opportunity to test various types of octane boosters.

They found out that:

1. Most standard octane boosters from petrol station stores are crap. They use Toluene to get a higher octane rating from the same fuel, yet the small dose means only a fraction of a point is gained, to get good results (like going from 91 octane to 99 octane) 1/5 of the entire fuel tank should be pure Toluene.

2. There are a few types of specialized octane boosters (Nulon, NOS Octane, Wunda, Wynn's, STP) which do work, they may gain 1 to 3 points, but they are hard to find.

3. The station petrol has better octane rating than nominal - that is, a 95-octane petrol is in the 96-octane range on the test machine. The reason for this is the mandatory ethanol content in the petrol. Ethanol has poor energy density, yet very good octane rating, on the other side refinery petrol has very good energy density and lesser octane.

Since the mandatory ethanol content is to be increased in the near future, from 5% to 10% on all petrol types and later to higher values, we can expect a slight improvement in ratings of pump fuels.

~Nautilus

 

[Miss Chief]

I've been running my 180 on VPower for the past couple of months, probably around 6 or 7 tankfuls and while it does seem a little bit smoother and more responsive (although it could just be me imagining it!) I do know that I get anything from 20-30 miles more from a tank of the good stuff. Worth it for the couple of extra quid at the pump IMO.