After 4 months with my 200, an answer...

[MarkCup]

...to the question...should I run my 200 on higher octane fuel?

I've done some science, and come up with the following...



Firstly, the accountant in me is obsessed with working out the true cost to me of this car, so from day one I have religiously recorded every penny spent using Fuel Log (Android app). After 4 months and almost 6,000 miles I think I've got enough data to support/dispel the myth surrounding higher octane fuel.

Run on 95 from purchase switching to 99 RON fuel early in February, the graph above shows the actual calculated mpg for each fill up over 2,000 miles on each fuel grade.

Mileage covered is mostly minor A and B roads, is consistent from week to week, and my driving style varies from enjoying the car as Renault intended to being on a mission to extract the absolute maximum mpg I can get. Fuel was provided by Tesco.

Headline figures are (95 v 99);
Fuel price = 135.9 v 140.9
Average mpg = 33.08 v 35.87
Cost increase = +3.68%
Mpg improvement = +8.44%
So higher octane fuel costs more, but you go further on it.

Cost per mile;
95 RON = 18.68p
99 RON = 17.86p
Saving from running 99 RON = 1.18ppm, -4.369%

Doesn't sound much?

That saving, over a full year covering;
6,000 miles p.a. = £81
12,000 miles p.a. = £163
18,000 miles p.a. = £244
24,000 miles p.a. = £326

I for one am sticking with it...not only is the throttle response, flat spot, and general driveability at low revs massively improved, at 18k p.a. I get almost 4 full tanks for free over a year.

 

[smiler]

so im saving roughly £244 give or take a year using a higher octane fuel :0

and there i was thinking it would only improve performance and not the money in my pocket haha

 

[BREENY BOY]

Well done for having the staying power to bring us those figures mate much appreciated. I knew I was talking sense when I told the misses that even though I was paying more for v power in the long run we r saving money. Intact I'm taking thus to her to prove it lol

 

[N0ddie]

Thisis what I've been saying since I had my VXR. Nobody would believe me.

 

[Gareth_197]

I thought everyone knew this anyway lol. But please dont put 95 in your clio from tescos!!!

 

[tiababy]

Oddly I'm finding the opposite.
I've run my clio on 99ron (tesco) since buying it last year an averaged 30mpg across the 8k I've done.
I'm 2k in using 95ron and am averaging 31 over that 2k shall see how it goes as I have now got the money to run it on 99 again (only on 95 due to service tax and insurance tyres etc since January) but I'm trying to do 8k on this and decide then what works better for me.
Mine is done on a/b roads, motorway and town driving.


This could also be down to me driving slightly more frugally since January though, as before that mpg didn't bother me as much.

 

[Benmc]

This is really good idea bud! But wouldn't how cold it is outside have a big effect too?

 

[deadmau5]

I'd use higher octane fuel if the mpg was the same!

 

[Ollie RS]

thanks for your findings

 

[MarkCup]

This is really good idea bud! But wouldn't how cold it is outside have a big effect too?

Arguably it will...lower temperatures I believe increases the density of the fuel, so when it's colder, you'd get higher mpg from the same volume of fuel.

If that is the case, the savings would be even greater...as the early running on 95 RON was when temperatures are lower, so its mpg has been enhanced by the cold weather.

I'm going to carry on with this...so easy to record each fill up with a simple app. Not just fuel though, I've got everything right down to the air freshener and iPod lead costed into it LOL

 

[Mentalpen]

Bugger all this MPG frugalality , RON 99 and make use of it !

I get mid 20's in the 200 and high in the 265 Trophy but its still in the running in period.

You don't buy an RS to worry about running costs and if you have you have got the wrong car. I'd rather spend 2 quid a week extra and enjoy it and keep the engine clean than put something that keeps a 1980's pug happy.

 

[930Tech]

But please dont put 95 in your clio from tescos!!!

Why's that?

 

[A2ON]

GREAT THREAD.

If you buy a performance car ( The Clio is just about this ) Then putting high octane min 97 octane is should be a must .

 

[Foxspeed]

good write and well done :thumbup1:

figures to back up evidenace rather than just "i think its better"

 

[shurm]

Great info cheers.

 

[fmp]

Excellent work mark.

I have run mine on 'super' from day one. Glad I did!!

 

[Willis]

Excellent work mark.

I have run mine on 'super' from day one. Glad I did!!

+1 and +1.

Good work Mark, very insightful.

I'm the same FMP, only ever used the good (expensive) stuff.

 

[Gareth_197]

Why's that?

Generally the cheap 'supermarket' fuel is diluted slightly with poor additives, 99/ v-power is less prone to pinking ect. Because of the higher quality additves involed.
Higher octance fuel will always increase drivability, mpg and just a healthier fuel for your engine which is why i choose it, it would be good to see something like shell 95 vs tesco 95 or the same with the higher ron fuels.

Just my 2pence worth.

 

[stephengreen]

Arguably it will...lower temperatures I believe increases the density of the fuel, so when it's colder, you'd get higher mpg from the same volume of fuel.

If that is the case, the savings would be even greater...as the early running on 95 RON was when temperatures are lower, so its mpg has been enhanced by the cold weather.

I'm going to carry on with this...so easy to record each fill up with a simple app. Not just fuel though, I've got everything right down to the air freshener and iPod lead costed into it LOL

Interesting post. You'd need to repeat experiment using 95ron fuel in warmer temps to even the findings out. Colder weather lowers tyre pressures and hardens the rubber increasing rolling resistance which may offset fuel and air density. With diesels fuel consumption definitely increases in very cold temps but suspect the oil companies add anti freeze type additives to diesel which lowers the calorific value

 

[Ollie RS]

Generally the cheap 'supermarket' fuel is diluted slightly with poor additives, 99/ v-power is less prone to pinking ect. Because of the higher quality additves involed.
Higher octance fuel will always increase drivability, mpg and just a healthier fuel for your engine which is why i choose it, it would be good to see something like shell 95 vs tesco 95 or the same with the higher ron fuels.

Just my 2pence worth.

I don't know if you are talking about tesco's momentum ron99 fuel as well, but when i had my previous turbo'd car it ran far better on tesco 99 than on v power, i got more pops from the exhaust and it generally felt more responsive, mpg was the same as v power though...