USING 97 Superunleaded petrol

[tumbleweed]

Hello Ive had my 172 since the beginning of December...since Day 1 I have run it mostly on Optimax(98+Ron)...on the odd occassion I have put in small amounts of unleaded (95Ron) and the difference was noticable (Only when no shell garages about).

Using Optimax the green change gear light would come on at 6500 in second gear and an annoying 6750ish in third which is abit close to the rev counter.

Today I have run the optimax down to the reserve tank area and done another 33 miles probably travelling on fumes...then I filled it up with Total Superunleaded (97ron)..put £35.17 worth in the tank and the needle was off the top ....15 miles in on the way home i tried putting my foot down....

Results were I felt a greater surge during acceleration than using Optimax...the second gear green light comes on now at 5750 rpm and 6250rpm in third...stopped and started a couple of times on the way home and it has remained consistant with green light change up recommendations. It feels very quick!!!!

Anyone know why this is?....the car had a tank full of superunleaded and it was 4oC outside.

I may convert to superunleaded for a while...your thoughts please...

 

[Tom]

odd?

i thought the green light was preset

 

[tumbleweed]

That is what I thought as well....I hope someone can shed some light on this...maybe it is an ECU thing going on...going out ina couple of mins...to try it again!!

 

[ak_uk]

The gear change light isnt regulated by engine/oil temperature like the rev limiter - is it?

 

[clean16v]

I KNOW!! i am sure i had the exact same feeling, on optimax my car would feel quick but it would die after around 100miles, then if i put 95ron in the car would feel quick again(around 100 miles) and then normal again. this would carry on happaning. the clios have knock sensors, i reckon that they advance/r****d the ignition for the different type of fuel you put in therefore when you switch petrol the car feels very quick byt for some reason the knock sensor doesnt like it. these are just my thought and they could be absoloute rubbish but it seems to be the only explanation. when i posted a topic asking whether this was the case, no one knew

 

[Tom]

maybe its when maximum power is reached

 

[tumbleweed]

The car was warmed up....it has felt gradually slower on optimax over time and worse on the unleaded stuff....but it has whooosh......just been up and down the local dual carriageway and the change up light was the same...cannot tell you at what revs it changes up at in 4th...worried about getting a ban and usually concentrating solely on the green light and not the rev counter

 

[scott8629]

So your saying the change green light comes on earlier with SUL than Optimax???

But you are getting better results with SUL?

Scott

 

[Frosty]

Well the shift light is linked to oil temperature. It comes on at around 6250 when the oil is not warm, then raises to 7000 when it is.

I have heard some negative thoughts on Optimax (from automotive engineers, not pub experts) which I wont go into, but have run my car on it from day 1.

Im going to try some super unleaded (say Esso) and see what happens.

The Renault brain cannot detect the octane level of the fuel, but can make minor adjustments to ignition timing. Why this should affect the shift light remains a mistery.

Laurence

 

[tumbleweed]

Yes exactly that...the green light is coming on earlier after changing to SUL...in third using optimax it was up to 6750 before the green light....but it is still now down to 6250 in third and 5750 in second...I will post fourth gear change up tomorrow night after I have tried it.

In fact tomorrow I will post full first, second, third and fourth gear change up on green light revs.

 

[Frosty]

When does the limiter kick in though (when the car is fully warm)?

 

[scott8629]

Thats odd, I have Optimax in mine at the moment so I will try it out on mine tomorow so we can compare.

Scott

 

[tumbleweed]

I try and stay away from the rev limiter area....but i did hit it on the last outing tonight and it was in the 7000 region where it normally is.

Going to figure out the Oil tempature thing as well...try it when the water temp says it is middle gauge and again fourty miles down the road to see if change up light differs on recommended change up speeds.

For my test I used Total superunleaded and filled it to the top of the tank.

 

[scott8629]

My water temp gauge is one notch above the middle when warm is all of yours the same?

Scott

 

[tumbleweed]

No mine is bang on in the centre...always has been and the coolant l evel under the bonnet is full

 

[Fred@BTM]

Simple answer = it was built by RENAULT!!!!

 

[Viv172]

The sticker on the inside of my fuel cap says 98 ron recomended, but have been putting in standard 95 ron unleaded in as the dealer said, am I wrong??

 

[RobFenn]

No, but as you say its recomended, you will only get your full 172bhp with Optimax or an equivalent 98ron.

In my clio optimax is better, i was getting better MPG when i trialed both fuels over a week. Ive also taken the car on the same stretch of road and reached a 4mph better top speed with optimax, and as far as i know, my car wasnt designed to be any better using it.

 

[Viv172]

dumb question but... do I have to wait until I have an empty tank before putting in some optimax or can it be mixed with standard unleaded??

 

[RobFenn]

Yes amazingly dumb question!

Yeah you can though obviously it wouldnt be a full 98 ron until you filled it up again afterwards

 

[Viv172]

Thanx Rob will go and try it...

 

[tumbleweed]

Still running Superunleaded....will go back to Optimax this weekend...once i have run optimax for a couple of tank fulls i am going to try Octane booster which should be good since Optimax is 98+ or 98-99 octane fuel.

 

[Simon172]

After reading this i decided to have a go with 97 octane from esso garage. I read somewhere that optimax is SUL with additives in it including octane boosters etc. I dont know really. Some impreza driver was saying that his impreza went quicker, but idled rougher on 95 and smoother and slower on optimax.

I put in 97 today and it felt pretty quick, but it always feels pretty quick so im not sure how id guage it. The fuel guage was reading almost red when i filled it up with £15 worth. Im going to run 97 for a while and see how it feels/goes.

 

[tumbleweed]

I think with SUL the performance on a private road from 100-125MPH is an absolute revalation...quicker than Optimax I think...going to conitnue with SUL for a couple of weeks..then go back over to Optimax...probably try it with octane booster as well along w ith group N replacement air filter from Demon Tweaks.

 

[Frosty]

Octane booster will not make an ounce of difference mate.

 

[RobFenn]

Well theres no reason why it wont, those additives can clean your engine and also up the ron to over 100+ so you could get a few bhp, i read in a mag someone RR his car after using an additive gave 10bhp, he was so impressed he didnt reveal what the additive was!

Optimax isnt as simple as that, it cleans the intake system and being high density it helps MPG something SUL or normal petrol arent. So its a misconception that its expensive cos it works out just as cheap per tankful. The reason it doesnt feel any quicker with it in is because its not just a boost, it improves performance and responsivness over the whole rev band. SUL is just cleaner petrol without MPG gains!

I sound like a salesman!

 

[Tom]

i read some where that impretzas had a command line in the ecu that upped the boost when you use 98 ron fuel

but it takes a while to work

3-4 fill ups

it was in autocar years ago

 

[RobFenn]

I think on imprezas its as much as 10 bhp they lose by not using optimax isnt it? Is it the same for the new ones?

 

[Steveold]

I dont think its the fuel your using..... we all know optimax is the best fuel... I just think cars have good days and bad days......

 

[Tom]

thats true my car last night felt like it had 150bhp

 

[Steveold]

lol.... but you know what i mean? sometimes mine feels really slow and has trouble getting past 105 then other days i get 120

 

[Frosty]

Octane boosters dont do much at all. They are just made to suck in the Max Power generation. Most products will claim they can HELP raise the RON level by 3-5 points, but they mean 10th of a RON e.g. 95 RON plus octane booster will give you 95.5 RON.

Another example, A Skyline owner had to fill up with 95 RON so used and octane. His car is fitted with the PowerFC fueling ECU and reports detonation. He had to run the car at 0.3 of a bar lower than usual to get rid of the det. This is because his octane level was (95 + 0.5 = 95.5 RON)! As a result he had to run much lower boost - 0.3 of a bar is 4.35 PSI (0.3 * 14.5) - and he probably paid more for and octane booster and 95 RON than he would have for plain old 97 RON.

Both these examples are straight from the horses mouth - not stuff my mates mate read in a magazine!

 

[Viv172]

This quote is on the BP web site what do you think?? will it improve performance?? It is 95Ron

How will BP Cleaner Unleaded affect the performance of my car?

BP Cleaner Unleaded contains a new additive package with advanced detergents to keep your engine clean and improve engine performance.

 

[Steveold]

Yeah but optimax is 98ron and has cleaners etc too

 

[RobFenn]

It hasnt been proven though, Shelll have done a huge amount of testing to prove it was worth investing millions in creating a better fuel, not just cleaner petrol. BP just make claims to compete, theyre more bothered about opening up stupid cafes!

Frosty basically there are some blag additives and ones which work

Steve- Probably because day to day driving doesnt loosen the engine up and get oil circulating, on a long run your car will be better.

 

[Frosty]

Optimax is around 98.6 RON when it leaves the refinery, but by the time it has found its way out of your injector its probably a fair but lower.

Independant tests have shown Optimax to degrade after around 40 days of it being created. In this time it has to be loaded onto a tanker, transported, stored at shell, purchased by me and you, and then used - all within 40 days.

Super Unleaded has much more resistance to degrading, and so in the name of research, my car is coming off a diet of Optimax and on to a diet of Esso Super Unleaded.

Results to follow...

 

[RobFenn]

You need to get out more!

Anyway point is i know my cars better with optimax and thats all the justification i need.

 

[damianshaker]

never noticed a huge difference in power with optimax over standard 95 ron. It kind of feels a little faster, but to me not worth the extra couple of quid per full tank. Ive started using essos super unleaded and found it makes a big difference. The car runs smoother, it feels a little quicker and idling etc is alot more consistent. Its worth noting however in France and most of Europe, their super is all 98 ron unlike our 97. Why do they get the extra 1? Not only do we pay more for fuel, they get an extra octane. I think a campaign should be started.

 

[tumbleweed]

Still using SUL and still very happy...not to phased about going back to Optimax either!!