RON95 vs RON99

[Shamaz Majid]

Apologies if this has already been discussed, but being new to the forum, I did do a search but could not find the answer.

My question is whether 99 RON fuel should make any difference to a petrol E280 (year 2000)?

For the last 7 years I have used RON 95 (with no issues) but recently filled up my car with Momentum99 and am 2/3 through the tank. I have to say that so far, it has made no noticeable difference what so ever, either to performance or MPG.

On the other hand, the same fuel has made quite a difference to my Nissan 300ZX, perhaps due to a different fuel map.

Any feedback would be great.

 

[AndyPCD]

To be honest i dont think it will make any difference to the mpg or performance of this sort of vehicle.

I agree with you on the 300ZX as my evo X has to run on 98ron and this is all down to the way the engine is mapped.

I have had to run my evo on 95 ron before and you can feel the difference in the car.

The only difference it will make to running the e280 on 98ron is to your wallet!!!!!

 

[MarkJunedd]

A couple of weeks ago when we went through France my car would run like a pig on the normal 95 ron unleaded so I changed to the 98 super and it made a massive difference, although the 95 in france also contains 10% ethanol so that could have the reason. My wife filled the car today and automatically put super in it so i'll see if its the same story this side of the channel.

 

[Alps]

tesco is 99 RON and doesnt hurt the wallet either!

 

[NISFAN]

Hey Shamiz Majid, your E280 will go much faster using 99 octane, but only because your wallet will be much lighter.

Turbo charged cars usually benefit from high octane fuel as they suffer from knock. The high octane (anti knock number) reduces knock, allowing the ECU to advance the ignition for more power.

This is not the same for N/A engines, so very little if any difference will be noticed.

 

[BlackC55]

I get another 30 miles to a tank on V Power with a n/a V8

 

[steve333]

tesco is 99 RON and doesnt hurt the wallet either!

With respect i wouldn't put any supermarket fuel in my car,getting back to the original post, i have used both 95/99 & found that the later does give an extra mid 20mpg over a tank but i mainly add it every 4th tank just for it's cleaning qualities

 

[Shamaz Majid]

This is not the same for N/A engines, so very little if any difference will be noticed.

Actually my 300ZX is not the Twin Turbo but the N/A version. Nevertheless, I think the fact that it's a Japanese import as well as chipped probably means that it can take advantage of higher octane fuel.

It is certainly smoother and quicker with the higher RON fuel.

 

[flango]

Actually my 300ZX is not the Twin Turbo but the N/A version. Nevertheless, I think the fact that it's a Japanese import as well as chipped probably means that it can take advantage of higher octane fuel.

It is certainly smoother and quicker with the higher RON fuel.

Ah with that information then yes use V power and it will take advantage of the higher octane, that car is designed to run up to 102 RON fuel. So if your wallet can stand it certain BP garages do 102 RON, last time I used some in the Scooby it was £4.56 per litre Yes per litre = £20.70 per gallon. Use it for rallying which at 3 mpg is not funny but bloody quick

 

[moonloops]

With respect i wouldn't put any supermarket fuel in my car,getting back to the original post, i have used both 95/99 & found that the later does give an extra mid 20mpg over a tank but i mainly add it every 4th tank just for it's cleaning qualities

Both Tesco 99 an Shell V-power reduced knock and improved performance on my 320BHP Subaru impreza type-R, and on also my 280 BHP Subaru legacy twin turbo.

Supermarket fuel has same RON/MON but without additives IIRC

BP ultimate was not as smooth.

99/vpower in my CLK500 makes no difference at all. It makes a smallish difference in my MR2 turbo.

As stated above, it's all about how aggressive your ECU is at adapting to fuels, and long term how the detergents keep you engine "clean".

In an older merc - just buy the cheapest fuel and spend £6 on redex every year.

 

[Palmball]

I definitely find that 99RON makes a difference in my C63...in fact, the guys that dyno'd it last week and got 20bhp more than AMG quote (507bhp actual vs. 487bhp official) put at least 10-15bhp of this down to the fact I always use 99RON!

 

[cromerelegance]

hi, I have used 99RON variously and found a siginifcant difference in my Porsche Boxster 2.5 and my wife's Megane 1.6. both had improved performance and mpg. In general I have found that the extra price at the pump(BP) is returned in the improved mpg's. My present car E320 (1997 75k) is more difficult to assess and I rarely use it on long runs but would be surprised if there was no difference. I never use supermarket fuels unless in a bind with no choice. An odd tank here and there is probably fine but I would rather have decent fuel with additives than have my engine slowly deteriorate because no cleaners or lubricants are present. Yes, presume you can use Redex for same purpose but is is likely 6 of one and half a dozen of the other!

 

[NISFAN]

I definitely find that 99RON makes a difference in my C63...in fact, the guys that dyno'd it last week and got 20bhp more than AMG quote (507bhp actual vs. 487bhp official) put at least 10-15bhp of this down to the fact I always use 99RON!

Not knocking the power figure, but I would not rely on a dyno figure as being accurate. A dyno is a good tool to provide before/after figures, but that is all.

The figures given by MB would be from an engine dyno, and therefore 'engine flywheel' figure. A rolling road dyno will show a significantly lower reading, as it only gets fed the power 'at the wheels', after all the losses through the drivetrain/tyres. The dyno then 'calculates' an at the flywheel figure.

Truth is, put a car on 10 different dyno's and you get 10 different figures, all 'estimated'.

Best practice is to get used to 'power at the wheel' figures, as they are going to be a little more accurate. Only the calibration of the dyno, and ambient conditions will affect reading.

 

[martin_a]

With respect i wouldn't put any supermarket fuel in my car,getting back to the original post, i have used both 95/99 & found that the later does give an extra mid 20mpg over a tank but i mainly add it every 4th tank just for it's cleaning qualities

Actually Tesco 99 is one of the best you can get. It is guaranteed to be 99 RON. Shell Optimax is slightly unstable it could be 99 if fresh or 98 if it has been sitting. You'll notice that there is no RON rating advertised at Shell pumps...

I used to have to put super in my Scooby, as the Nissan is a Japanese import then yes, as Flanaia said, it is actually built for much better quality petrol and 95 RON will automatically retard the ignition and give a bit less power.

With the Merc, its not really built for high revving performance so i doubt you'd get any benefit for the extra costs.

m.

 

[flango]

Actually Tesco 99 is one of the best you can get. It is guaranteed to be 99 RON. Shell Optimax is slightly unstable it could be 99 if fresh or 98 if it has been sitting. You'll notice that there is no RON rating advertised at Shell pumps...m.

Thats a very good point about Optimax, V Power or whatever they call it this week. Marketed in UK as 99 RON but in the rest of europe as 100 RON, the actual spec is between 98 RON - 100 RON for UK, so it will vary anywhere between that. Tesco 99 RON is exactly that and why most club racers use it as you know its the highest RON fuel you can buy at sensible prices so will give maximum power, V Power is a bit of a gamble in that respect.

 

[steve333]

Actually Tesco 99 is one of the best you can get. It is guaranteed to be 99 RON. Shell Optimax is slightly unstable it could be 99 if fresh or 98 if it has been sitting. You'll notice that there is no RON rating advertised at Shell pumps...

I used to have to put super in my Scooby, as the Nissan is a Japanese import then yes, as Flanaia said, it is actually built for much better quality petrol and 95 RON will automatically retard the ignition and give a bit less power.

With the Merc, its not really built for high revving performance so i doubt you'd get any benefit for the extra costs.

m.

Tesco's might well be 99ron but it doesn't have any cleaning additives & for that reason alone i'm happy to use shell

 

[BTB 500]

Shell Optimax is slightly unstable it could be 99 if fresh or 98 if it has been sitting. You'll notice that there is no RON rating advertised at Shell pumps...

Hang on a minute. Optimax was 98 RON, and only ever advertised as such.

V-Power is 99 RON, and that's widely stated e.g.

"Shell V-Power has an octane rating of 99 RON"

Shell UK launches Shell V-Power – providing its customers with ‘Ferrari fuel for the road’. - United Kingdom

"Shell V-Power is also a high performance fuel (99 RON)"

"Shell V-Power also has high, 99 RON, octane quality "

Shell V-Power high octane fuel - Overview - United Kingdom

So I would be very surprised indeed if it wasn't (advertising standards, sale of goods, etc.).

 

[martin_a]

You are buying a brand though. Seriously, go to Germany, V-Power is clearly labeled at the pumps as 100 RON. We don't get the same quality stuff in the UK but given the spend on sponsorship they make sure the brand is the same everywhere.

EDIT worth noting Tesco's supplier puts up regular independent quality checks on the website. They argue that with a new engine their fuel is cleaner anyway and therefore doesn't need cleaning additives. Even Shell only claim it cleans old dirty engines, if you've looked after it and used decent fuel then you shouldn't have any issues.

m.

http://www.greenergy.com/Buying/fuel_certificates.html

 

[BTB 500]

Grades and specs. are different on the continent ... we were actually in Germany last week. E.g. they (Shell) have 'Racing' branded fuels there - that may well be the 100 RON you mention.

The links I posted were Shell UK, describing the UK products. If you have evidence that that's not the spec. of product being sold on the forecourt then take it to trading standards. Like I said, I would be very surprised indeed if that was actually the case.

 

[BTB 500]

OK confirmed that in Germany they sell "V-Power 95" and "V-Power Racing" (100 Octane), as well as the standard FuelSave grade:

Shell Kraftstoffe - Deutschland

Not the same as "V-Power" in the UK.