Shell 'Optimax'

I make regular Chester > Edinburgh trips and have always had to fill up on arriving. Driving style is usually irrelevant as I don't do 'slow'.. So how did I manage to retain another 50 - 60 miles worth of fuel in the tank on Optimax.. And that was with trying to break the Moffat > Penicuik land speed record (As usual).. Which I did

-A-

P.S. Any members of the Scottish constabulary who read this.. Yes.. I know you have speed cameras at Lamancha.

Hello Petrolheads, hello Rana,

yeah, I've been following the thread with curiosity. I would broadly agree with Rana and re-state what several people have already said regarding engine tune. If the engine is not mapped to utilize higher octane fuel then there will simply not be any gains from using that fuel.

Euro spec engines will generally be mapped using reference grade 95RON ULG, but if fitted with a knock sensor (or sensors) they can be tuned to run up to the Detonation Borderline,(or DBL ha ha) taking advantage of the additional knock protection of higher octane fuel.

The performance improvements from using 97 or 98RON would be very vehicle specific - for example I think that the early Rover K16 was not limited by detonation above 4000RPM so would show no increase in power when using anything above 95RON. Not sure about that though.

I am not quite as cynical towards Optimax as some however. If you can detect a difference between 95 RON and 97 RON then you could probably detect a difference between 97 and 98RON. Difficult to carry out an objective test in your own cars though.

Regarding the engine cleaning properties of Optimax ? Well yeah, why not ?. I'll take it at face value, but I'd ask if the detergent additive is so good then why isn't it used in all Shell branded fuel ?. Again results very specific to different engines/combustion chambers I would guess.

Overall then, a nice attempt to sew up the high octane market, possibly with benefits to the consumer ?

Aftermarket engine tuning ?. Think you can do better than us, huh ? Well do ya punk, huh ?

Well good luck, buy a fire extinguisher and a tow rope.

Regards,

Brian OReilly

quote:

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Originally posted by Brian OReilly:

Aftermarket engine tuning ?. Think you can do better than us, huh ? Well do ya punk, huh ?

Well good luck, buy a fire extinguisher and a tow rope.

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I see that both JP Montoya and Ralf Schumacher have taken up your advice on a number of occasions this year..

-A- (NOT a Ferrari fan btw...)

JN,

Well it does sound as thought you have dotted your I's and crossed your T's wrt tuning your car.

The only reason that I asked was that my query to my Toyota insider was brought upon by an experience that my wife and I had one day a few years back.

I was driving my wife to work one morning when a hopped up Honda decided to shed its transaxle all over the road in front of us. I had to do some pretty creative manoeuvring to avoid ripping my oil pan off.

The young driver was luckily none the worse for wear, but his car wasn't quite so fortunate as its front right wheel decided that it really wanted to go its own way (another strike against front wheel drive?).

The poor little bugger had a horribly sad look on his face as I helped him pick up his car parts off of the roadway. I gave him my condolences, reminded him that he was lucky to be alive and offered to drive him to his destination. He was grateful but declined, deciding instead to stay with the deceased.

For me the moral of the story is that unless one is prepared to cover all of the bases it is best to leave the 'engineering' up to the manufacturer.

YMMV (whoops),

Craig

PS. I use Optimax Gold in both our cars (VW turbos) as the manufacturer specifies 91 R+M/2. Many vendors round these parts offer 92 to 94 though I can't say that I've noticed any difference between Optimax and the other vendors closest equivalents. BTW, our valves and injectors never get a chance to get dirty

Dev,

If you by any chance pick up on this do you know anything about high octane BP Ultimate that is rumoured to be launched in the UK in October?

Cheers

Dave

Sorry to be boring and drag this back on topic... I used Optimax from time to time in a 1.8 and the performance improved along with slightly better fuel consumption. This over 60,000 miles and all very subjective. In the last four motnths I've racked up 11,000 in a 2.8 and the car does feel a bit sluggish unless it's Optimaxed. Fuel consumption is around 3% better - less noticable than on the previous car. No, I don't have a degree in fuel technology and I can't say that isn't all in my head. I don't know where the Shell garages I use get their juice from and what's added or not added. All I know is how my car feels. So I'll always go for Optimax when I can and if that's contary to other peoples knowledge or experience then fair enough. Each to their own.

As for the merits of graduating from the Ayrton Senna school of motoring (fast, incisive and dead), the power of marketing over engineering and how to trash your car on a track, I'll leave that discussion to those with more knowledge of "real driving".

Oh, and BMW ROCKS! There. Now I've said something decisive and expect to shot down accordingly.

Cheers

Harry

Having used Optimax for sometime in my Corrado VR6, i can say that it has made a difference, it responds better and it is smoother.
I don't know why! but it is, and in my opinion if you own a high performance car it is worth the extra cost.

Since my last post I've been Optimaxed for about 5000 miles. A defenite improvement in fuel consumption over that time although I'm unconvinced about smoothness and pick up. Yes it's good, but how relatively good it is I couldn't say. I'm now using the stuff in preference to anything else without even thinking about it, so my brain appears to have made the decision.

Dave,
It seems that BP Ultimate is only 97 octane, but has similar cleaning properties to Optimax. Therefore, it should be cheaper than Shell's offering.
Tony

Thanks, Tony.

I have some further testbed experience of Shell Optimax compared to my last post of just over a year ago on this topic. I work for an engineering consultancy and my last three years have been spent leading the design and development of new high powered production engine that will be on sale next year.

1. Like I said in my last post, on modern engines with adaptive knock (detonation) control systems that are tuned at higher octanes, the benefits of are clear. However, after completing the development work on this engine I can add that even if the calibration is fixed at a lower octane (say 95RON), Shell Optimax at 98RON may give an improvement in the suppression of transient knock and especially so in warmer weather (>25degC). What I mean is that when you put yor foot down quickly, if there appearance of knock in one or more cylinders, the control system will then act and reduce the ignition advance (as quickly as by the next cycle) on the offending cylinders. This is usually more apparent to the customer during warmer weather unless a manufacturer has not done his transient fuelling work to sufficient detail (some don't), in which case this will happen at cooler temperatures aswell. A higher octane rating can suppress this knock and maintain performance levels. Having said that, even standard pump-grade 95RON is nearer 97RON so only the more sensitive drivers will notice the difference at 98RON.

2. Shell Optimax does indeed have a good additive pack (I'm not saying its better than Texaco or BP, I don't know because I have not done the back-to-back test). After a very severe durability test on one of our engines specifically on this fuel, the condition of the piston crowns was cleaner than normal. We also had no fuel injector deposits which we suffered when using a known lesser-quality additive pack on the same test. I don't remember the valves looking any different.

I also tried Optimax on my own car which is calibrated at 95RON but adapts down to 91RON (a VW 2.0 engine with a well developed engine calibration). I noticed an improvement in transient response during very hot summer days. I aslo got a 3% improvement in fuel consumption compared to standard, possibly down to the suppression of hot temperature knock. There was no improvement at lower temperatures.

Hope this helps.

Rana

All very interesting stuff.
I always thought that petrol was petrol was petrol, but now I will shove a few tanke of Optimax through my Alfa GTV 3.0 V6 and see what happens.

6 months ago I became the owner/driver of a new Audi A2 1.6 FSI. Every fill up since has been optimax, This week my local petrol station ran out so I filled up with regular. Performance in every respect was noticeably poorer within a few miles, enough to ensure future fill ups with Optimax.
Larry

Is it just Optimax,or Shell petrol in general ?

I have not tried the Optimax stuff,just the normal unleaded,but what i have noticed is that if I run my car on Shell petrol,it seems to run better & have a bit more "get up and go" But if I run it on Texaco or the stuff that Tesco,Asda etc sell. For some reason,it seems somewhat "flat" by comparison.

I just happened to comment about the Shell/Texaco thing when round at my parents & my father,(who has a diesel) uses Shell for the same reasons .

(can't really comment on any of the others,such as B.P. as my normal driving habits seem to dictate Shell / Texaco)

Puzzled

Chris

(Car = BMW E39 M52 engine)

quote:

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Originally posted by Chris Brandon:

I have not tried the Optimax stuff,just the normal unleaded

(Car = BMW E39 M52 engine)

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Chris, you should have a close read of your owner's manual. BMW recommends running their cars on Optimax (or equivalent spec).

John,

Just dug the manual out......
Quote....

Spark-ignition engine with catalytic converter

The engine should be run exclusively on unleaded fuel.Since the engines have a knock control function,they can run on different grades of fuel.

Minimum fuel grade: Regular-grade unleaded fuel(octane number 91,Research method).

The rated performance and fuel consumption valuesare acheived with :

Premium-grade unleaded fuel (octane number 95,Research method)

This fuel is also known as: DIN EN 228 or Euro-Super.

For higher performance and lower fuel consumption,it is also possible to use

Super Plus/premium fuel ( octane number 98,research method).

So,it "should" in theory run on most unleaded. But curiosity is something I was born with in excess,so might just have to try Optimax for a couple of months and see how I get on.

But,whichever this pans out,my car just seems somehow happier on Shell as opposed to Texaco

Time to get some breakfast

Regards

Chris

quote:

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Originally posted by Chris Brandon:
So,it "should" in theory run on most unleaded. But curiosity is something I was born with in excess,so might just have to try Optimax for a couple of months and see how I get on.

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Interesting the different wording for different series with what I thought were the same engines. My 3 series manual says "Super Plus 98 RON - run the engine on this fuel grade by preference, in order to achieve rate performance and fuel consumption."

I think it is really just semantics. The tune itself will probably be identical, but the wording reflects the availability of fuel grades at the time of release and in specific world markets - ie initially only 95RON unleaded gasoline was widely available, now 98RON and above is commonplace.

If the handbook said use 98RON for optimum performance, but you could only find 95RON, then you might be concerned.

Hope you enjoyed your breakfast ?

Regards,

Brian

Brian..."Hope you enjoyed your breakfast" ?

Certainly did ! ... So much so in-fact that I had to visit the "Big Fat Xmas B*stard" thread

Regards

Chris