944 S2 - K&N and Optimax?

[zcacogp]

Chaps,

Quickie.

I have a 944 S2.

Will using Optimax (and other high-octane brands of fuel) make any difference to the performance? Some people say it does, others swear it doesn't.

Also, do people use K&N air filters in these cars? I always used one in my Golfs, as it made a difference and saved money in the long run. However, they seem more pricey for Porsche applications. Where is the cheapest place to buy them from in the UK (see my other thread here:

http://pistonheads.com/gassing/topic. )


Oli.

Edited 'cos the link didn't work.

Edited by zcacogp on Monday 19th June 12:05

[Harry Flashman]

Optimax will have an effect in terms of engine cleaning – but unless you have an aftermarket ‘learning’ chip, you won’t get the benefit of the higher octane rating, performance wise, as the ignition will not remap itself to take advantage.

Don’t know about the K&N, but I don’t like them as anecdotal evidence (and my own experience with a K&N equipped MGB V8) suggest that they allow dust into the engine, that increases wear.

[aasc]

I think S2's are set to run on 95 RON i.e. standard petrol, whereas turbos & 968's were 98RON i.e. super. Although Optimax is rated at 95 RON it allegedly has 97/98 RON content so is effectively Super. Will it run much better - probably not noticeably but should be better than running on supermarket-range fuel.

[HAB]

Isn't Optimax 97/98 RON?

It would be fair to say a K&N filter would'nt make any difference to performance. I think Porsche know how to design an efficient intake system, and the filtration remarks above would put me off anyway.

[softinthehead]

optimax is rated at 98RON. never noticed any difference in my old 2.7 944 but as said, the engine management wasnt meant for it. the S2 will probably benefit from the higher octane rating - my stepdad's S2 certainly seemed more urgent compared with running on bogstandard 95RON. my 968 certainly does but then it has a promax chip. as to the K&N filter, cant say ive noticed much difference with mine and i will probably swap back to standard at the next service

Oddly i get the impression that mine goes best, and is most fuel-efficient, with BP ultimate, which is 97RON.

Edited by softinthehead on Monday 19th June 16:48

[vixpy1]

Harry Flashman said:

Don’t know about the K&N, but I don’t like them as anecdotal evidence (and my own experience with a K&N equipped MGB V8) suggest that they allow dust into the engine, that increases wear.

Also, they are oiled filters, which in my experience kill the MAF over time. Best to stick to a non oiled filter if you can

[Harry Flashman]

softinthehead said:

optimax is rated at 98RON. never noticed any difference in my old 2.7 944 but as said, the engine management wasnt meant for it. the S2 will probably benefit from the higher octane rating - my stepdad's S2 certainly seemed more urgent compared with running on bogstandard 95RON. my 968 certainly does but then it has a promax chip. as to the K&N filter, cant say ive noticed much difference with mine and i will probably swap back to standard at the next service

Oddly i get the impression that mine goes best, and is most fuel-efficient, with BP ultimate, which is 97RON.

Edited by softinthehead on Monday 19th June 16:48

By the way chap - thanks for all your advice a few weeks ago - I bought one just like yours! Except cobalt blue rather than midnight. And I love it.

[Harry Flashman]

vixpy1 said:

Harry Flashman said:

Don’t know about the K&N, but I don’t like them as anecdotal evidence (and my own experience with a K&N equipped MGB V8) suggest that they allow dust into the engine, that increases wear.

Also, they are oiled filters, which in my experience kill the MAF over time. Best to stick to a non oiled filter if you can

Charlie speaks the truth - wasn't an issue on my old MG, bit would be on a modern car...

[zcacogp]

Hmm, so the concensus is "NO" to K&N's, and a cautious "YES" to Optimax ...

Thanks chaps.


Oli.

[semprini27]

My 2p worth.....

Previously used K&N 57i kit on a '95 BMW 525i - definately helped. I've also used K&N filters in my grasstrack and rallycross racing days and NEVER had a problem with dust getting through - and you would not believe the amount of crud thrown up at a dry and dusty grasstrack meeting. So thumbs up to K&N from me. So there !

My 3.2 Carrera runs best on Tesco 99 RON with Optimax running a close second. AT all costs avoid Total fuel - it's rubbish IMHO.

[softinthehead]

Harry Flashman said:

softinthehead said:

optimax is rated at 98RON. never noticed any difference in my old 2.7 944 but as said, the engine management wasnt meant for it. the S2 will probably benefit from the higher octane rating - my stepdad's S2 certainly seemed more urgent compared with running on bogstandard 95RON. my 968 certainly does but then it has a promax chip. as to the K&N filter, cant say ive noticed much difference with mine and i will probably swap back to standard at the next service

Oddly i get the impression that mine goes best, and is most fuel-efficient, with BP ultimate, which is 97RON.

Edited by softinthehead on Monday 19th June 16:48

By the way chap - thanks for all your advice a few weeks ago - I bought one just like yours! Except cobalt blue rather than midnight. And I love it.

well done that man. i think cobalt blue is a beautiful colour - would have been my first choice but as youve probably guessed, the pool is fairly shallow when sourcing a good 968 cab, especially manual. midnight blue looks good, but its a bugger to keep clean. btw, if you get a sports exhaust, you'll also get that tvr sound youve been hankering after....