Shell Optimax

[Rudders16v]

Does anyone else run their car on this?

I used to run my Williams on normal petrol, and for £20 i would constantly get between 135 and 150 miles.
For the last 3 fill ups of £20, i've been using Optimax. And i've got 141, 148 and 156 miles from each £20's worth.
I always fill up as soon as the petrol light comes on constantly (i ignore the flickering it gives you for the first few miles of getting low) and always put in £20, so the mileages i get from each fill up should be a reasonably fair comparison.
But although it looks like Optimax may be giving me slighty better MPG (although this is just about cancelled out by the extra cost of Optimax in the first place), i've not really noticed any improved pick-up/smoothness that i have in other cars i've run on it.

[northy]

i only use optimax in mine mate - so ive no idea if its added benifit or not.

but the higher ron must do somthing.

[Swervin_Mervin]

Optimax every time. Trading standards proved that the only claim Shell could make that was true about it though, was that the cleaners in it do actually work.

So my engine should be nice and clean inside after 10k miles on the stuff.

[TomS]

Yes I use optimax in my valver

May be more expensive but I think it's worth it

Tom

[KingStromba]

I use Optimax, unless im caught short, in which case an main garage super 97 RON unleaded to get me to a Shell station.


I am currently writing an artical on fuel RON and MON for this site. Be finished in a few weeks hopefully.

[Jan]

i use optimax or BP ultimate - might as well hey :?

[FATBOY]

so has anyone felt or seen anything different from using this stuff???? i just use normal unleaded! but if i was to switch to this will i notice anything different? apart from the bigger hole in my pocket!

[KingStromba]

Also worth bearing in mind that the pump RON is not the true RON, and the pump RON is actually an average figure of the MON and the RON.

So optimax isnt 98 RON, its actually slightly less. So 95 RON fuel is also slighlty less. So although the manual says 95 RON fuel, if you put 95 RON fuel in your car you are actaully putting in 93 / 94 RON fuel.

RON = research Octane number
MON = motor octane number

RON is the ability of a fuel to prevent knocking in a test engine under high load (the higher the number the better it prevents the knocking). MON is the ability of a fuel to prevent knocking in a test engine under low load. The more octane (or octane equivalents, ie heptane, toluene, pentane, hexane) in the fuel the better the fuel will prevent pre-ignition in the cylinder.

Ron on the pumps is an average of these two numbers.


RON was invented as a way of standardising fuel during the first world war, as too many planes were being lost due to excessive knocking caused by poor fuel quality control. A bad batch may see half the planes of a squadron lost to mechanical failures. The octane was added to prevent knocking and thus prolong the life of the engines as they were constantly at high rpm and high load.

Note : Proplong the life of the engines, by preventing knocking. If you run a chip / remap, you almost certainly need to run 98 RON fuel or higher. If you run the car at high load with a chip remap, you certainly need the 98 RON fuel.

[Jan]

The octane was added to prevent knocking and thus prolong the life of the engines as they were constantly at high rpm and high load.

That's why most people use the better stuff - it's more to do with how we drive our cars than the engine itself actually requiring it

if i just pootled about in the clio i would definitely just use 95 :wink:

[KingStromba]

Correctamundo

[Rudders16v]

so has anyone felt or seen anything different from using this stuff???? i just use normal unleaded! but if i was to switch to this will i notice anything different? apart from the bigger hole in my pocket!

Well although it's more expensive per litre, the extra cost seems to be balanced out by a slighty higher MPG, so you can do the same miles for the same pennies

[Dilusi]

so has anyone felt or seen anything different from using this stuff???? i just use normal unleaded! but if i was to switch to this will i notice anything different? apart from the bigger hole in my pocket!

I had to fill up with normal unleaded last month and my 172 was definately a bit down on power and was very hesitant and lumpy especially when cold. Filled up with Optimax the weekend and the car feels loads better, picks up a lot quicker and feels generally a lot smoother. I don't really notice any difference in fuel economy like some people though, I always seem to get about 25-26 mpg whatever I put in.

PS DONT use that BP Ultimate crap its awful my car runs even worse on that stuff than normal unleaded. Oh and don't use Sainburys super either as thats BP.

[Enid]

I have no doubt at all that my car runs a lot smoother on optimax. Every so often I have to put normal unleaded in it and the idle is much lumpier. Optimax also seems to iron out a few flat spots through the rev range as well. Good stuff, would recommend it.

[Lunner]

Filled up wiht Optimax before FCS, certainly havent' noticed any gain in performance, but it pops nicley on the down shifts now

[Rudders16v]

Yeah i've noticed a bit more of a burble from the exhaust when changing down to

[scotte666]

150 miles for £20. maybe i have a leak or a heavy right foot.

[Smokey McPot]

Usually use Optimax of Ultimate....Elf Super is 99RON

used some Texaco regular at FCS.....its running alright on it at the moment. :)

[KingStromba]

Elf?

[Smokey McPot]

Yeah.....although i think its all Total now....anyway, they used to have 99RON Fuel.....

[KingStromba]

Yes total = elf

[BRUN]

Total Super is defo not 99RON, not yet anywayz, they are bringing out a new fuel that might be 98RON, but the current super is 97RON from Total stations

[Allan]

i was talking to a tanker driver about an hour ago at tescos garage and aparently the fuel about here comes from some place in essex and its the same stuff they supply to merco, texico, tescos, total and shell, they fill there takers from the same pumps and also pump it to all the garages so all just as crap lol, he reconed BP was the way to go, for the purest stuff anyways (ron 95) didnt get time to talk to him about the super stuff.

Need to take samples of all the fuels and test em

[northy]

lol...you and stromba need to get together to write a report...williams recommended fuel !

[VIPERONE]

optimax = gimmic

[Rudders16v]

150 miles for £20. maybe i have a leak or a heavy right foot.

Well lets just say im not exactly gentle with the go pedal. My 150 miles is probably broken down into about 10 miles city centre stop/starting, 40-50 miles sensible driving at about 60, and the rest normally bouncing off the rev limiter. Thing is, i've been getting more and more miles from the Clio ever since i've had it, think it could be cos its getting cleared out now whereas the previous guy used to dawdle around for his 3k miles a year

[2 live]

hhhmmmmmmmmmm 150 to £20...........thats fukkin good that

mines mapped to run on optimax so owt less really and u can feel a slight difrence in pick up..maybe its just me tho

fcs i had just over 3/4 tank optimax...had to fill up at donny services.....130 odd miles away summat like that...£37 i believe......gunner??

[KingStromba]

i was talking to a tanker driver about an hour ago at tescos garage and aparently the fuel about here comes from some place in essex and its the same stuff they supply to merco, texico, tescos, total and shell, they fill there takers from the same pumps and also pump it to all the garages so all just as crap lol, he reconed BP was the way to go, for the purest stuff anyways (ron 95) didnt get time to talk to him about the super stuff.

Need to take samples of all the fuels and test em

Independent laboritory tests i have read have shown that Esso tends to have the lowest amount of impuities. But then thats what a filter is for.

As for coming from the same storage depot yes thats true, the tankers have to unload the fuel somewhere. But where was the fuel actually REFINED? Shell, Esso, BP and other major brands tend to refine their fuel in this country. Supermarkets buy fuel from whereever they can, so yes, sometimes it may be a BP refinery, but sometimes it may be from Eastern Europe.

And all the major retailers do get their fuel from the same few refineries, but they add different additives and have different stipulations for fuel distilation. Just because it comes from the same refinery doesnt necessarily mean it the same fuel. Just as not all the products that come out of my lab are the same product.

[KingStromba]

I can get 208 miles from a £20 of optimax :D

[Dilusi]

I can get 208 miles from a £20 of optimax :D

WTF, do you coast everywhere? I usually get 250 miles out of a tank and the last time I filled up it took £38.

[Rudders16v]

I can get 208 miles from a £20 of optimax :D

208 miles? Thats a hell of a lot of times to run your car out of the garage, polish it, then put it back in the garage! :lol:

[snakeylady]

only ever use Optimax - ever - I get around 345 miles out of a tank [never run it to empty as soon as the needle gets towards empty she's filled up]

[willy55]

only use 97 ron or above but aint noticed that much difference i did in my 205xs that gave it proper power

[BenR]

stromba mate, might want to double check your info as MON tests are conducted under higher RPM than RON and thus more indictive of high load knock resistance.

Ron is certainly always higher than MON, but its the unpublished MON were in terested in so you can subtract it from RON to get the fuels true det sensitivity index.

*thumbs up*

[KingStromba]

RON would have to be higher than MON, as the rpm for RON on the test engine is 600, whereas its 900 for MON. So a 98-octane petrol (optimax) has the same knock resistance as a mixture of 98% isooctane and 13% n-heptane, but about 10 points less than that for MON. I also thought the loading on the RON and MON tests was different as well as the rpm, but i cant remember my petro chemical lectures that well.

[BenR]

RON is the ability of a fuel to prevent knocking in a test engine under high load (the higher the number the better it prevents the knocking). MON is the ability of a fuel to prevent knocking in a test engine under low load. The more octane (or octane equivalents, ie heptane, toluene, pentane, hexane) in the fuel the better the fuel will prevent pre-ignition in the cylinder.



Just what you said here thats all, wrong way round.

[KingStromba]

Ahhh, probably drunk or on ephedrine :D

[MrAtego]

Well mines been run on Optimax since new (except for about 20 litres when I was stuck) so I don't know if there is a difference in the 182, but I tried it in my old saxo and it def made a difference.