Fuel

[Guest]

Hi,
Does any one get better performance from Shell Optimax or the BP equivalent?

Do most ppl use unleaded or super unleaded?

thanks

Amo

 

[Guest]

I use 'cooking' unleaded - too mean to spend the extra 5p odd per litre.
Works fine.

Ok, different car, but...

 

[John Sims]

Does any one get better performance from Shell Optimax or the BP equivalent?

Yes

 

[Guest]

I used Shell Optimax in my old 944s found it much better that standard fuel.

With my new car I only use the Optimax because its over 98ron which is recomended. Only use BP or equivalent if can't get to a Shell garage as they are only 97 ron.

For the extra five pence you will feel the differnce within a month.

 

[944Turbo]

Yes, optimax, its more consistently cheaper than the other 'supers' .
Tony

 

[Mikie_gb]

I can't comment on performance, but my 944 S and previously my 535i obtained 10% better fuel consumption which is easier to quantify using optimax.

 

[usermjg]

hi
i have a 924S which i guess is the same and i have always ran my car on super unleaded and its been fine, loves it [] and i have owned the car for 8 years so i think its ok

Marc

 

[danmason]

That's right Phil, the car should have no problems with unleaded; as Marc says, Super Unleaded is the way to go for best performance... I'm an Optimax man myself.

 

[Mikie_gb]

Shell Optimax and BP ultra got a right slagging in one of the broadsheets this last weekend. Their conclusion was that short term results might increase high end power by no more than one BPH and may in fact decrease mid to low end.

I use Optimax in both my current Porsche and my previous BMW 535i and cannot percieve any difference in power, which is subjective in daily urban driving unless the change is large. I do however return 10% better average fuel consumption, which is why I continue to use Optimax, working on the principle that the engine is running more efficiently.

As to the cleaning effect.... Well the 16 bent valves that came out of the engine 12 months ago looked great. One of them is on the mantle piece....

 

[944Turbo]

I read that, but they only tried it on a Focus and only 1 gallon not that scientific really. Some modern cars (Subaru) take time to advance the timing to take advantage of the higher octane and some cars wont be able to get any benefit if they are running their maximum permitted advance on standard unleaded.
Tony

 

[Mikie_gb]

What stops me thinking I am buying £250 worth of snake oil every month is the improved consumption on exactly the same route week after week. And the the increased unit cost is offset by this.

 

[Fen]

That Sunday Times "experiment" was so flawed I considered writing an email of complaint, which is not something I do often.

Evo did a proper long term test on Optimax 18 months or so ago using 3 of their Fast Fleet cars, and then actually stuck a camera in the plug hole to look at the condition of the engine internals and it basically does what it says on the tin. I find my cab goes noticeably better on Optimax if I run 2 or 3 tanks in a row. The first tank after a period of cheap-skatery with 95RON unleaded makes no noticeable difference though, it needs at least 800 miles IMO.

 

[Hairyarse]

The S2 is setup for 95 RON so regular unleaded. People will often say that the car will feel a tiny bit more responsive with super but MPG wont improve as far as I'm aware. That said, supposedly you should have the timing set up for a particular fuel so in reality the biggest difference you'll notice is in your wallet!

I ran my S2 on 95 with no problems, my square dash spec is 98 RON so I use super although have filled with regular a couple of times and noticed no difference

Cheers
Andy

 

[sawood12]

Yes, your car as will any, perform better on Super Unleaded. Not necessarily because you're exploiting all those extra RON, but because you have a better chance of your fuel actually having 95 RON's in it! Though you are buying 95 RON fuel, you're actually probably getting something slightly less. This is due to the dilution of the fuel due to contaminants in the distribution network and with older fuel in your tank. So if you buy 98 RON you will probably end up either 95-ish RON and therefore be running more optimally with regards your ECU mapping.

Wether or not it is worth the extra pennies is another matter and will be upto the individual and how much of a difference they perceive.

 

[Lowtimer]

I wouldn't bother with Super on most normally aspirated 944s which have 95 RON in the handbook. On a Turbo, especially a tweaked Turbo, yes, I use 98.

 

[944 man]

Most 944s built state '98 RON' inside the filler cap. They dont require lead, but they do need the the higher octane.


Simon

 

[Lowtimer]

My mistake then, I thought it was just the early N/As that required 98.

 

[944 man]

My 1987 had a 98RON sticker in 1992, long before unleaded was common..... Moving forward twenty years I have a 1989/1990 which also wont run on 95RON.

924Ss ran on 95RON, until their final model year, IIRC.


Simon

 

[lookingfora944]

Some interesting responses.
The question only came about as I have a 5p off a litre voucher from Tesco which effectively makes super the same price as normal. I need to put a full tank in as I'm driving down to Dorset next weekend. So maybe I will fill it completely with Super and see if I really do notice a difference

 

[Wardy 944]

My car runs far better on super, I won't use regular unless I really have to.