95 RON in a Clio 172

[Tripps]

Thought I'd give some different fuels a try, even though the fuel filler cap recommends 98 RON. Last week did 97 and that was fine over a variety of runs, so have given 2/3 a tank of BP 95 a try.

So far it's running fine, even though the car has a Group N ECU, but I just wondered if what I'm doing is wise and what everyone else uses...

[Mr Jenks]

Stick with the recommende 98 or better still Tesco 99 (clubcard points as well) lots that I see at work with running issues are cured with better fuel.

[davo172cup]

i put 95 in my 172 cup and it was really jumpy on idleing. much smoother on 98(optiax).
id stick with 98/99 for the smoother tick over.
just out of interest, what group N ecu have u got, where did u get it from, you got any other mods and does it make any improvements?

[Tripps]

davo172cup said:

i put 95 in my 172 cup and it was really jumpy on idleing. much smoother on 98(optiax).
id stick with 98/99 for the smoother tick over.

Yeah I've found that too after a good run today and a short blat yesterday, my experiment will be terminated tomorrow when I top up with half a tank of Optimax

Alas, I've no Tesco 99 within a sensible distance

davo172cup said:

just out of interest, what group N ecu have u got, where did u get it from, you got any other mods and does it make any improvements?

It's the Renaultsport one, got it with the car when I bought it, along with uprated shocks and springs, Brembo cross-drilled discs, braided hoses and an adjustable strut brace - full details in my profile.

I've never driven another 172 Cup so can't really compare, but I managed to keep a 4.5 Cerbera and Griffith 500 honest on dark and damp country lanes on the first day I had the car, so it can't be too bad

[_deejay_]

Mr Jenks said:

Stick with the recommende 98 or better still Tesco 99 (clubcard points as well) lots that I see at work with running issues are cured with better fuel.

Sorry for the hijack - but Mr Jenks, did you get my mail about the brakes? Been trying to get hold of you, to no avail....

[Mr Jenks]

Hi Deejay
No, I did reply to one but I'll try again now
Dave

[_Deejay_]

Mr Jenks said:

Hi Deejay
No, I did reply to one but I'll try again now
Dave

You have a reply, though it was to the same address so I hope it arrives!

[pbirkett]

98 RON is recommended for the 172 / 182, and as such, my car has always been given 98 fuel. Apparently, it only makes the book BHP figure with 98 fuel, which is why a lot of owners claim they dont develop the book power figure, because they are penny pinchers who wont put the right fuel for the car in.

[Tripps]

pbirkett said:

Apparently, it only makes the book BHP figure with 98 fuel, which is why a lot of owners claim they dont develop the book power figure, because they are penny pinchers who wont put the right fuel for the car in.

I've learnt my lesson now - no more penny pinching for me. Filled up with Optimax today and went for a session and all is now smooth again.

[panthro]

Used 95 on mine, it didnt like it. Swtiched back to Optimax. Tried tesco 99 once and will never use it again. My car absoloutely hated it. Felt worse than the 95. may have been a bad batch........

[Tripps]

panthro said:

Used 95 on mine, it didnt like it. Swtiched back to Optimax. Tried tesco 99 once and will never use it again. My car absoloutely hated it. Felt worse than the 95. may have been a bad batch........

Hmm... Not tried 99 in the Clio yet, as I forgot to fill up in Sevenoaks yesterday - doh! But it's curious you say yours didn't agree with it, the previous owner of mine used it all the time and said it ran great.

A lot of TVR owners say their cars run better on it than Optimax but mine doesn't like it much, I guess the bio component must be a hit or miss depending upon how the engine is tuned...

[Yugguy]

I occasionally put 95 in my 172, only when I really had to, and never liked it, the car always felt blunted, you could definitely feel the slight degredation in performance.

[dotdog]

only run mine on optimax.. it does show, when have to use 95 i just don't rev it..
had a group n remap at k-tec, new forest, - she now revs to 7800... that is 70 in 2nd and 100 in 3rd..!!
has transformed the overtaking ability.. recommended.

[dcw@pr]

i had been using only 98/99 until recently, the last few tanks I put in 95. Have had no idling problems, and there's no way I can notice a few bhp difference

[Tripps]

You could feel mine disliked the 95 under load, at 4000rpm and above you could feel the comparative lack of urge. Mind you it's chipped, so might be mapped for 98 only.

[stu_00]

Anyone been using BP Ultimate ?

Find trying to keep to shell is hard, as not always a garage when you need it.

I have used the Tesco 99 seems ok. The best fuel is in Germany, the 172 loves 100 ron both V-Power and Ultimate, wish we could have some of that. Makes the car smooth as silk.

[Tripps]

stu_00 said:

Anyone been using BP Ultimate ?

Tend to use it most of the time on mine (probably had 3-4 tanks of it since I've had the car) as there aren't any Shell garages really close to me in terms of time. The car seems to be very happy running on it and I haven't found an obvious performance difference between BP Ultimate and Optimax, unlike the performance I got with 95 octane which was noticeably worse.

You'd imagine the 172 was tuned specifially for 98 octane, as that's what it says in the fuel cap - I guess it depends upon the tolerances in place.

stu_00 said:

I have used the Tesco 99 seems ok.

The previous owner of mine said that was the best fuel for it, I'm going to fill up at Tesco in Sevenoaks tonight and see how it goes using the secnic route home...

Edited by Tripps on Thursday 17th August 12:56

[stu_00]

The 172 Cup you have sounds like a good nurbergring sub 8 mins car !


Tesco 99 is produced by www.greenergy.com/products/99_octane.html

The only thing is that it might not contain the same cleaning additives as Shell, but as the octane rating is so high should burn cleanly i would of thought.

Be good to get an expert opinion to see if it is as good as they say it is.

[Tripps]

stu_00 said:

The 172 Cup you have sounds like a good nurbergring sub 8 mins car !

I think that's what the previous owner had intended before his wife had other ideas, it's certainly kitted out quite well, the only unabused area I can see is induction which I might have a play with at some point, he'd gone for the sensible suspension/shocks and brake changes first before changing the ECU.

stu_00 said:

Be good to get an expert opinion to see if it is as good as they say it is.

EVO did a good article earlier this year (possibly last year), alas they didn't include Tesco 99, due to availability I think.

As I recall their finding were that Optimax (and other supers) could be of use if a car was engineered to adapt to it, with different ignition timings etc. In some cars they found the 105 octane+ racing fuel under test had little effect on performance, while in the M5 there were differences of 50bhp between one end of fuel spectrum to the other.

The other thing they found that was of more use was to use fresh fuel from busy forecourts, as the good stuff in it evaporates so quickly in can really degrade performance. They had some bad batches of Shell 95 that performed worse than the supermarket stuff.

So using super-rated fuel in an area where no-one else does could be considered a no-no as you'd lose the benefit of those 2/3 extra octane points...

[stu_00]

Any ideas how to find out if the garage sells a lot of optimax then?

I have heard this too, so think it is a good idea to consider this notion. In practice it maybe harder to tell.