98Ron Vs 95Ron

[RazeVRS]

The only perceptible difference I can tell is indicated on that Focus pic - loses a bit at the top end (10% or so?). Feels like the 160PS Scirocco I had before rather than the 180PS vRS it is. Its marginal though - and I do see a drop in mpg (normally a couple of mpg on like-for-like journeys).

I agree,upto 4500 rpm I.e. normal daily commuting range,negligible gains. If your going to talk about the upper end gains ,don't bother to mention economy though! :-)

With 180bhp roller skate ,if I drop 10bhp, I doubt I'm going fret going nowhere on the M25 this evening

[Ootohere]

That might be how it is for you.

I find that at 2500 rpm or below with no stress on the engine and no Turbo being used it can run smoother and more economically at Motorway Speeds.

Cold starting may be smoother.

Its not just about Maximum RPM/Torque.

But if you find no difference, then your fine as you are.

Others that do pay attention to fuel usage can find an advantage of 99 Ron used with a Twincharge

when just driving on roads @ National Speed Limits.

If its a case of 5 pence a litre more, (23 pence a gallon, or £2.07 a Tank ) but you get an extra 15-20 MPG out of that 9 gallons, its paid for its self. If you get better than that you are gaining.

If economy matters you can just use the 95 ron and also just go slower, or the 99 ron and go slower..

The difference when using 102 ron say in Mainland Europe can be very noticeable.

george

[philhoward]

Would love to get another 15mpg - did you mean 1.5-2.0mpg, George?

I'll be putting some 102 in for the trip home...

[Ootohere]

sorry, i meant an extra 15-20 'miles' out of the 9 gallons. ('MPG' was the mistake.)

george

[philhoward]

[Jabozuma]

Blue line = 95 ron

Red line = 98 ron

Car is a Ford Focus RS, completely stock.

This shows you that Ford RS is very much tuned for top end and suffers from poor combustion at lower end. RON95 being more volatile (the lower the RON the faster it burns) helps to combust the mixture better at low rpms. Then it starts detonating and ignition has to be retarded robbing motor of power-that's why RON98 shows gains in higher rev range. vRS runs around 2-5 DEGs advance top end (with AFR as rich as 9.5:1!) and high teens below 4k rpm on 98 (AFR14.7:1). Not tried 95 yet. That's all stock.

[pipsyp]

Ran mine on 95 ron for 6k due to fuel card restrictions not allowing super unleaded having run it on BP Ultimate for 5k and in all honesty noticed no real difference in performance.

[Jabozuma]

Ran mine on 95 ron for 6k due to fuel card restrictions not allowing super unleaded having run it on BP Ultimate for 5k and in all honesty noticed no real difference in performance.

You must be running it at full chat to notice any difference really. Theoretically even at low revs you should be able the get better economy with RON98 as it allows for more spark advance making more power. However, if like with Ford's example low rpm is problematic anyways then lower RON fuel will help.

[Jabozuma]

What really is important in fuel is MON number and percentage and type of additives. Anybody knows those for say Shell Nitro and Momentum?

[Ootohere]

At the weekend i was looking to see if there were many comments online about 'Nitro',

Not seen it at many Shell Stations.

Did not find much comment on it other than the Launch stuff.

so,

I was reading a wee article the other day on the 1980's launch.

& the fact that the great 'Magic ingredient' was 'Sodium Chloride' back then.

i will find it and post just shortly.

george

EDIT

[icemanmjm]

Ive used momentuem 99 for 6 months and to be honest it was good, but i was only getting around 36 mpg, and that was on a good run so i thougt lets have a look at this nitro, and ive now been getting well over 40mpg, performance excellent as well, so wont be going back to momentum99.

[Ootohere]

Tesco Monentum 99 all winter @ most of the winter on Dunlop Sports Maxx Tyres @ 2.4 bar

& easy to get 45 miles per gallon average. 405 miles for a 9 gallon brim, not Displayed figures.

So Tesco Momentum will do me fine.

Same trips this weekend, much the same speeds, but warmer weather and Pirelli Zero Nero tyres on and not getting 42 MPG from the 9 gallons.

So the tyres will go, and the Fuel will be staying as Tescos because of the amount of triple points i get,

but. I will give a couple of Tank of Shell a try to see once i am back to getting my 45 MPG.

george

[Jabozuma]

Tyres have massive effect on fuel consumption. A member here was reporting 7% increase in fuel consumption when he changed to different tyres, of a high performance sticky but still road variety.

I am feeding Brunhilda de Beemer with nitro+ diesel from Shell. Will see how that one goes. SWMBO complained bitterly when she had to pay for 65litres of it last time lol.

[Ootohere]

I measured side by side for the comparison the 205/40/17 Pirelli against my spare 215/40/17's on wheels but off the car, same external size (total diameter) exactly.

The Dunlops in 205/40/17 that much less total diameter than the Pirelli of the same given size..

(even allowing for some wear on the Dunlops.)

http://www.kouki.co....size-calculator

george

[RazeVRS]

I measured side by side for the comparison the 205/40/17 Pirelli against my spare 215/40/17's on wheels but off the car, same external size (total diameter) exactly.

The Dunlops in 205/40/17 that much less total diameter than the Pirelli of the same given size..

(even allowing for some wear on the Dunlops.)

http://www.kouki.co....size-calculator

george

If I understand you, the Pirelli tyres have a larger diameter & circumference than the Dunlops for the same given size?

That would help explain why your mpg would appear to have dropped for the same given journey, ( less mileage being recorded per journey )

[Ootohere]

It would if i trusted the car Mileometer to measure my miles covered.

But the fuel is used is actual for the miles i do on the same trips week in and week out in different vehicles.

First thing always when changing tyres sizes is to check the accuracy of the speedometer and mileometer.

(on a vRS, 215/40/15 often give a more accurate reading than the standard fit 205/40/17,

but as i am pointing out, Marking on sidewalls do not guarantee the actual sizes matching.)

george

My daily drive is 10% out on the Mileometer reading on its current tyres, 60 mph on the speedo is 69 mph actual,

sometimes its only 5% on other tyres,

you get used to making the adjustment and allowance, checking with Satvav and knowing your fuel use.

[philhoward]

Differing rolling radii for different tyres is a constant battle it seems; rarely are they ever exactly what they say they are. I can't help wondering if manufacturers take different tread depths to mean the actual size - new, half worn, fully worn etc. Sidewall construction/shape also seems to have an effect.

[Lewisb1989]

Been using Nitro+ for the last couple of tanks and don't know if its a coincidence but seems to have used a lot more oil than usual. Been using V-power and momentum since I've had it, 18 months. Oil usage has been steady at just under what it says in the manual but seems to have spiked a bit recently. Did a 100 mile round trip on a bit of an economy run with the cruise set at 60mph so get the consumption up to average 43mpg for this tank up to now. Then the oil light came on the next day. Has anyone else noticed a link/trade off between MPG and oil consumption and/or any adverse effect of Nitro+?

Edited 29 May, 2013 by Lewisb1989

[philhoward]

Had two enforced tanks of 95 (empty tank and no SUL available) and struggled to hit 360 miles to the tank. Back on SUL and have almost touched 400 miles on the tank again. Might not get to the Aral with its 102RON today, so 98 it will be, I think (unless I go the wrong direction tonight and get the V-Power racing 100RON stuff...).

[sharkrider]

ive used 102 RON in europe, and my car loved it... it seemed to "sing" !

[philhoward]

It does go better with the "good stuff"...

[MartynVRS]

When I first picked my car up new there was half a tank of 95 in it. Asked the dealer why and said it runs fine on it so that's all they have to put in it. Drove home, hitting the rev limiter the first few gears and felt OK but not that quick. Put it down to a tight engine and the 95. When I emptied it I filled up with V Power then had to go down the DVLA to cash my old tax in. Dad was passenger and there was an overtake on. Pulled out, foot down and it rocketed past. I thought fark me it wasn't like this earlier?! It's never had 95 since and got steadily quicker until I'd done about 12000 miles then stayed the same. Mine has never been good on fuel but given the journeys I do it's not surprising. I've seen 24mpg commuting in and out of Swansea. Seen 45-50mpg on a run but this was trying hard and as a new low I had 10.1mpg at Combe. Gutted I didn't get it under that I almost always use it's performance whenever I get the chance to.

[Jabozuma]

ive used 102 RON in europe, and my car loved it... it seemed to "sing" !

I will be trying that next week when I'm at Nurburgring

[philhoward]

Aral petrol stations for the 102RON, I think Shell V-Power Racing is 100RON

[Jabozuma]

Will have the peepers peeled for 'em Aral forecourts, thanks mate .