superunleaded fuel

[mlc]

we are still trying superunleaded in our two main cars - and I still think its a waste of time.

The websites of BP and Shell make interesting reading. BP claim an average increase of 3% for power, acceleration and economy - although I suspect not all at the same time. Shell claims lots of wonderful things but doesnt actually commit to values for improvement.

Using the BP claim of 3% improvement in economy. Thats amounts to less than 1 mpg for the average MB driver and would only be verifyable by keeping accurate records over months - during 2004 in my car I managed less than 20mpg on one tank when I sat in traffic all day and over 40mpg on a gentle cruise to the west country - a 3% improvment would be completely masked in most peoples usage.

Finally why is MB not recommending these fuels - if they really worked wouldn't the car builders all be recommending them! After all an advert that said something like "MB recommend BP Ulitmate - for an extra 5 BHP and 0.3 seconds quicker to 60" would be very powerful.

I could of course be proven wrong!

Mark

 

[mr. shr]

Finally why is MB not recommending these fuels - if they really worked wouldn't the car builders all be recommending them! After all an advert that said something like "MB recommend BP Ulitmate - for an extra 5 BHP and 0.3 seconds quicker to 60" would be very powerful.

Aren't all the figures at the back of MB model range brouchers based on using ron98 fuel? I'm sure I read somewhere that all S Class petrol engines should be filled with the expensive stuff.

I filled my W208 320 with BP's super fuel the other day. Still too early to notice any different but will keep you posted. But to be honest, I doubt I'll notice any performance improvement. The car runs soooo nicely as it is. I think the tiny little percentage figures that BP/Shell etc. quote will be untraceable. It's like winning a Lotto jackpot and then finding a fify pence piece behind the sofa: you just aint gonna notice it!!!!

But I am willing to be proved wrong!!!

Happy New Year to all.

 

[bigt]

test results

fanfare.....drum roll...........

Here are the results of the shell optimax run:

Previous mpg on the same run = 30 - 32. This is driving 95 percent motorway at a steady 70 - 80 mph.

Results on optimax = 31.5 mpg on the same run. Driving conditions similar with the exeption of:
a. Spent about 25 mins driving at 50-55 mph because of heavy traffic

b. Took about 20 mins of very slow stop start driving to get past an accident.

Conclusion - Arguably with the delay on getting past the accident could indicate that the optimax has sustained or even improved slightly on the previous consumption but at a nett cost of nearly 6 pence per litre more.
Incidentally my car is a 190E,2 litre, 14 yrs old with 126k on the clock.

These so called super fuels may work with a newer hight tech engine but seem to make no difference whatsoever in my merc with the low tech variety.

As a matter of interest, I asked the bloke behind the counter what the difference was between the fuels and his verbatim answer was " oh yes, its good stuff - its a higher octane and you will get about 100 miles more from a tankful".

I asked what eveidence shell could back this up with and he said he had read it in a shell leaflet at some time in the past, so it would be interestin to know what Shell used as a test vehicle and how big the tank was ????????

This may just substantiate my previous posting on this topic that they are all the same regardless of what brand. Would love to hear of anyone else experimenting like this.

A prosperous new year to all
Trev

 

[Myros]

super unleaded

I used to keep extensive records on my old BMW, and they proved without a shadow that super-u and the super-u/4-star leaded mix that I ran were about 3mpg more effective. That was on an 82 318i high compression (10.5:1)motor, no catalyst.
My C280 runs about the same comp ratio, and I get about the same consumption from Sainsbury's super-u,as I do from premium .I buy the super-u courtesy of 5p off vouchers. I notice the engine is lots sweeter and more responsive across the rev band, espec above 4,000. Perhaps the subliminal exploitation of the extra power accounts for the relative increase in consumtion of super-u.
The conditions I drive in here are too variable to ever do a decent back to back comparison, but when I go on my hols abroad I fill up with super-duper German and French rocket fuel (99 and 100 Octane super -plus) and the merc feel like it's going to take off and end up in orbit. There must be something in it.
By the way, my petrol flap sticker says super-unleaded, premium only as an exception.
I also found that fitting a Broquet fuel catalyst made miles more difference, as it increased the smoothness at idle, and makes premium work like super, and super work like super-plus.

 

[stwat]

I have recently completed a comparison of super unleaded (BP Ultimate)versus (Normal BP) unleaded and can conclude that super unleaded gives me approx 10% improvement in fuel economy (350 miles per tankful compared to 315 per tankful. I do a 100 mile round trip each day including town, B Road, A Road, and Motorway which provides a good mixture of different driving conditions. The car feels much more responsive and smoother using BP Ultimate over standard unleaded imo.

P.S. Stwat, your fuel consumption seems very high?

Sorry, forgot to mention, my tank only holds 55l. But from when the fuel light comes on it takes around 46l. the rest must be the reserve. so thats 206 miles from 46l of fuel.

 

[SLinKyjoe]

rite. done some testing with supermarket sludge, mixed a bit with BP normal unleaded and dashed to southampton and back via lardahn. (dashed meaning it took me 2 days, stopped over not slow driving!) squeezed 61litres in back home. not diffciult as it's a 70l tank. this is optimax time. first results are............................................................................................................

absolutly no difference at all. not even slighlty. car doesnt run better and no mpg inprovement.......however all is not lost. am due in sarfend at the weekend...christening you see. so another decent run and a bit more mileage and will report back. am not giving up on this. am gonna get an answer for all of us.

hope that traffic light camera that flashed me last time is still out of film....or someone else has a bill that was mine.....not that i would have gone through a red...no not me your honour, it was a yellow van wot did it, honest.

 

[guydewdney]

my tuppence...

400 miles to a tank = 20 mpg with normal unleaded.

440 miles to a tank = 22 mpg with super unleaded.

Repeatable, demonstrable etc etc.

I do a quick calulation in me head to see if the petrol is cheaper for me (i.e 10%)

 

[mr. shr]

400 miles to a tank = 20 mpg with normal unleaded.

Does that mean you've got a 90 litre tank? :?

 

[mlc]

the tank must be even bigger! 90 litres assumes that the tank is actually empty.

My tuppence worth is:

Mondeo 2ltr. No change in performance, could be upto 5% better on economy.
230SLK. no change in performance, could be as much as 10% heavier on fuel - could also be that I drove it more than MrsC recently and I drive it harder than her!

Conclusion: No change from my previous thoughts - if this fuel was so good on economy then everybody would be using it, and performance is only helped if your engine needed a clean out in the first place.

But the trial continues.

Mark.

 

[SLinKyjoe]

Right. 1800 miles of testing complete. the result. no differnce at all. I have used a fuel calculator program and checked the car average and it is suprisingly accurate. The only thing the car cannot get right is the amount of fuel left and distance to go. I had an indicated 2 miles before it ran out and yet only got 61 litres in it. (70l tank). it had averaged 29.8mpg. which was exactly as the fuel calculator worked out.

The car has been run on sainsburys unleaded 95 (which i have on good authority is BP). It has been run on Shell Optimax and then dropped to BP ultimate and finally standard BP. Mixture of tootling around an averege of 24mph and returned 29.9mpg on all fuels and at an aveagre of 45mph on some motoway runs and averaged 32.3mpg.

So either the car cannot tell it has rocket fuel in it or it adjusts to suit the parameters of that fuel without increasing performance.

The old scoobie ran like a bag of spanners on normal unleaded and didnt get any better until you reset the ecu and filled it with optimax. then it ran off to the horizon with your driving licence and left your bank balance in tatters.

So as far as I am concerned either where i live we have good fuel or it really is a marketing ploy. off shopping at sainsbury's where the tight fisted new management have decided that you only got 3p a litre off now.

 

[Wadswick]

Super unleaded etc.

I have just taken delivery of a new C230K, which has a supercharged 1.8 litre engine, giving an output of 192bhp. The petrol filler cap has a label on the inside which just says UNLEADED. After a few weeks of ownership, I flipped through the inch thick owner's manual only to find that the car engine is designed to take 98 Ron fuel and should be used, unless there is an emergency, when 95 Ron is acceptable to get over the short term problem. I had been filling the car up with normal unleaded. A call to the MB dealer I bought the car from and they said no problem with normal unleaded, they always supply all their customers' new cars with normal unleaded - "absolutely no problem and will not affect the engine in anyway". Now I have come across a great deal of correspondence on the matter on this webpage and others and therefore I am now totally confused. Surely there must be a definitive response to this "chestnut"?

An authoritive response please from anyone?

 

[mlc]

Wadswick,

Lots of discussion on here about fuel as you can see. MB state on their website that your car should use premium unleaded to DIN EN228. Thats 98 RON to you and me.

Your local dealer have also correctly told you that the car will run perfectly well on "Normal" unleaded. The discussion on here has been about whether the premium product is required / works bettter / saves money etc. and you will see that the opion is divided. I fall into the supermarket fuel is good enough camp.

your engine will adjust to which ever fuel you use and I am sure no harm will be caused. I also believe (it certainly used to be the rule) that it is a type approval requirement in UK for your engine to be able to use 95 Ron.

hope that helps.

Mark.

PS We gave up trying super unleaded because we couldnt see any difference in any of our cars.

 

[RhodieBill]

Hi, personally I always use 'Super Unleaded' preferably Texaco. If you have a motor with a 10:1 Comp ratio you should use this type of fuel I believe, especially at sea level. I know the 560v8's have a 10:1 , don't know about the others?

I even put the same in my Avensis, it gives far better performance in both cars, more noticable in the Avensis because the 560 is a rocketship anyway. I just prefer it, it just feels right.

The best way to test it to just put in a tenner when the tank is nearly empty, and then when nearly empty put a tenner of the other stuff, you will definately feel the difference, plus you don't have to wait so long to compare and it's more obvious.

Cheers dudes, Bill.

 

[tarmacsurfer]

Just a quick question all... I have a 1991 300 8v W124, would the ignition timing dial in the engine bay need to be adjusted for the 97/98 Octane Superunleaded from the 'S' setting??

Cheers

 

[louisjames]

after the LONG thread of super or standard, i tried optimax last week today, and it has a highly noticable improvment, on response, pick up and economy. i will now stick to using optimax.

 

[TheJim]

The s setting is for the superunleaded and n is for normal.
Bizarrely I tried super in my 190e a couple of days ago. (by coincidence it is a topic at the mo) and I have noticed that it feels more responsive and idles more smoothly. Don't know about economy yet.....

My Dad who has an A140 noticed no difference whatsoever.

But he used to work in the petrochemicals trade and he has informed me that the petrols at supermarkets are nowhere near as good as branded ones. The petrol is all the same until each company puts their additives in it. The octane, detergents and various other chemicals to prolong the life of the engine are all very different. Plus the quality control is better at the proper petrol companies, I know people who have filled up at cheapo places and had contaminated fuel. Not good. At the end of the day, you get what you pay for!

 

[tarmacsurfer]

The s setting is for the superunleaded and n is for normal.

Cheers TheJim! I have just changed the timing from 'S' to 'N' (as I am a cheap skate and I'm running on 95!) and it feels much better...smoother, starts better, sits at idel better, and almost seems quieter!?!

Next I will try some super to see what that will do.

Many thanks again!

 

[turnipsock]

As I work at Grangemouth I managed to contact the guy that runs the tanker depot and ask what goes on, as there all the petrol companies and supermarkets seem to get there petrol from there. Here is a little of what he had to say...

"All companies have there own additive which makes it a different grade when it goes out the gate. This additive is injected in at the loading gantry.
BP Ultimate Unleaded. This fuel probably puts many people of because it is 5 or 6 pence more expensive than ordinary Unleaded.
If I run to Sunderland and back which is approx 350 miles. With Unleaded my car computer states on return that I have approx 68 miles left to travel before I run out of fuel. If I do the same journey with Ultimate Unleaded my computer shows approx 170 miles left. For an extra £2 at the pumps I am gaining almost 100 miles"

Don't ever say this forum isn't well informed!

 

[jberks]

Ok, you've got me curious again!
Just filled up with normal unleaded again this morning. I will do a mileage check then the next 2 fill ups will be the "ultimate" stuff. (2 tanks a week so it shouldnt take long to prove) However, to get an extra 100 miles out of a tank, you have to be looking at the thick edge of 7+mpg improvement. I think this would show up quite clearly on the computer and I don't remember anything like that on mine last time I tried.
There was a thought earlier on, that the older models gain more than the newer ones. If this was on a 230E, it would be backed up. I didn't think the 230E had a trip computer - where were the readings from ?

 

[mlc]

I really want this super fuel to be true - but it never hangs together. Our friend states that he normally does 350 miles and has enough fuel for another 68 miles. The extra cost of the fuel is £2 and it costs 5 - 6 p per litre extra. That means that his car normally does 418 miles on around 36 - 40 litres of unleaded = around 50 mph. On the super petrol he manages the 350 plus another 170 miles left = 520 miles on the same (say) 38 litres = around 62 mpg.

Now correct me if Im wrong - but I think the only way you get 50 to the gallon, never mind 62 out of a petrol MB is you do half of the distance on the back of an AA truck!!

I really do want it to be true - but if it were then everyone would use this super fuel. Wouldn't all the supermarkets be pushing it as well? Surely their "green" credability would go through the roof if they could say save money and use less.

We tried it on all six of our cars. I really couldnt find any improvement and at 10 p a litre extra (in South Manchester) gave it up as a lost cause.

Mark.