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Hi peeps

I filled up with Optimax in Cannock last weekend. Its the business but I've just done a location search on Shell's website to find a local garage and guess what? None for at least 20 miles in any direction now I have to go to Market Drayton for fuel

Why do I have to go to Market Drayton for fuel you ask? Well, one tank of Optimax isn't enough is it? The first tank makes a wee bit of difference, cleaning and protecting the engine and all that, but its when you've gone through 2 or 3 tanks of optimax that it'll start to pay off, am I right?

And finally. Shell Optimax vs. BP Ultimate. Theres a BP garage in town. Less than 2 miles from my house. What's the difference between the two? BP is more desirable as its closer to home than Shell

Is one truly better than the other?

Cheers

I've been using optimax for a few months now and can say if certainly makes a difference, the top end does feel stronger, and its helped alot with the pinking too. There's something going around that bp ultimate is better for 8valve engines while optimax is better for 16 valve, I don't know if thats true or how they come to that conclusion, but optimax for me all the way !

Prash wrote:I've been using optimax for a few months now and can say if certainly makes a difference, the top end does feel stronger, and its helped alot with the pinking too. There's something going around that bp ultimate is better for 8valve engines while optimax is better for 16 valve, I don't know if thats true or how they come to that conclusion, but optimax for me all the way !

I use Optimax in the Lotus Carlton - it was designed for 98 Octane so 98.5 will do nicely - using std 95 will knock 40 bhp off the peak output and thats a lot in my book

BP ultimate as far as I know is not as high octane rating as optimax and I would assume that the ECU/knock sensor on an 8V can adjust to cope with up to 97 but no benefit can be obtained from going up any further so no difference on Optimax

16V engines I assume can benefit from a higher octane rating so like Optimax better

It's all in the maps






These aren't Polo ECU Maps - they are from work I did on another Bosch ECU - as soon as I find a 2nd hand 8V ECU I'll start work producing a chip for mine......

Fresh Optimax is the best pump fuel in the UK...

Although Ultimate is better than old Optimax.

I've read quite a bit about how Optimax goes off very quickly as it's not very stable.

Still good stuff though...

But not in my Fabia LMAO!

Goes off how quickly Josh ?

Prash wrote:Goes off how quickly Josh ?

*butting in* about a month before it starts losing it's octane level

I used to fill up with ASDA 95 RON petrol, but for the past few months I've been using the higher octane stuff to see if it makes a difference.

What I've noticed:

Sainsburys Super (97 RON) is exactly the same as BP Ultimate -- and a damn sight cheaper to boot. Whilst using either of these, my fuel economy increased from ~42-44mpg to ~46-47mpg, and the car felt a tad more fiesty.

Shell Optimax (98.5 RON) has reduced my fuel economy back to ~42-44mpg, but my car now feels quite a bit more eager to go. In fact, I've noticed that just taking my foot off the gas for a second and then gently putting it back makes the car want to surge forward if it's doing 2,500rpm or higher.

Can i use optimax in my mk3 saloon? and would i notice any difference u think?

Well, petrol's petrol really, you can use it in a lawnmower if you want... as for noticing a difference, probably if you're using cheapo regular stuff at the moment you'll notice a bit of a change, shouldn't think so otherwise. Personally I just use tesco regular unleaded, but that'll change as soon as I get my solo / electron cards upgraded to switch / visa's so I can actually buy petrol anywhere else

Optimax = normal fuel with octane booster in it

Ultima I believe is the best fuel u can buy. Uses the best from the barrel and is filtered abit more I believe.

Super market fuels are cheap and dirty


Ive heard Esso super unleaded is one of the best you can buy.

i remember reading in the papers a year or so back that the supermarket petrol stations use fuel that is full of additives to give the correct octane, but can actually cause engine damage. anyone remember this or know more about it?

i personally use optimax cos its meant to clean the cack out of the engine. when i use the BP ultimate i cant feel any performance difference between it and optimax, but maybe thats just me

Dunno if it'd do much for the likes of us, Metz, Groovy, 'n' all... low-tuned cars (even for 1050cc) lacking in knock sensors (or even, lacking in ECU) that can't really sense or adapt to what fuel's going in. The 1050 should be as happy on continental 91 RON as it is on Tesco's barrel-scraping additivatastic 95 to Optimax 98.5 octane... there might be a little extra power from the different burn characteristics, so on and so forth, but the engine timing, injector mapping etc wont be altered. Might do a little to improve engine life as well, i dunno - some kind of scientific proof is always what I'm angling for.

Then again the engine seems to have funky flat spots in various places at the moment, and a bit of a top-end fall off til it's warmed RIGHT through... if it don't disappear within a couple hundred miles of sorting out the oil and plugs, then i'll have to sample a tank of Optimax or Ultimate (whatever the 8v one was) and see if the situation improves.
Mind you the last fill and last topup were something red&yellow (Shell, Esso, erm.. i was desperate and didnt pay much attention ) and BP anyhow, so whatever the problem is it might be more deep rooted.

PS Bstardchild, what are those maps all about, the pics are so tiny I can't make out what point it is you're trying to make with 'em

PPS Supermarket petrol pumps were also using a lot of WATER until someones engine seized from it and they blew the whistle... switch to biodiesel... then you're in control of the quality, and are being more eco friendly to boot.

Its looking like a trip to my Sister's house at the weekend then... she lives in the aforementioned town where theres a Shell garage. Nuts!

But on the subject of fuel economy - my guage (sp?) is currently at 3/4s of a tank and I've done a little over 140 miles, which is better than normal I'm sure. Haven't changed my driving style at all, so can't be bad eh? I'll know better after tomorrow when I'm heading down to Bridgnorth (again!! My second home ) and there'll be another 60 miles on the clock...

Cheers

So how many mpg to you guys get outta your motors?

After my BMC air filter and my 17"'s i get s**t mileage hah

i havent measured it coz im a lazy mofo, but i swear its only around the 250 mark per tank !!

Calâ„¢

CalvinGTI wrote:So how many mpg to you guys get outta your motors?Calâ„¢

When I bought the 1.4 MKIV 8V I couldn't believe how poor the mpg was - I was struggling to beat 37mpg - I though for a min I'd bought a right duffer but I was too used to the way I could drive my old 1.3 Coupes S MKIII and rewarded with 41mpg plus

Full service done and a change in driving style to account for the torque profile and now it's consistantly returning between 47 and 51 mpg

5 days a week 1.5 miles to work and same home with other shortish trips thrown in

2 days a week maybe a run of 80-100 miles max depending on whats happening normally cruising at 70-75 mph - anything over that and the thing chews through fuel!!!

I've got a 200 plus mile round trip this weekend so hopefully it'll pull the current tanks average up as last weekend I was in the Monza at Billing so it didn't get used.

I reckon if I brim filled it and drove it on a longish run with some restraint I could hit 55mpg but to be honest it's too boring to do that