What's new
Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Design 911 supply Porsche parts, Porsche spares and Porsche accessories, to both retail and to the trade. Our Porsche product and accessory range includes brakes, exhausts, tyres, wheels and Porsche panels and interiors.

Wot fuel

L

luke

Trainee
Joined
21 Jun 2003
Messages
73
Following advice from the mechanic (Porsche expert) who lives next door to Shirleys Garage, I've been filling up with regular unleaded. Engine seems to run well & plenty of power etc, but not having run a 993 before, I've not really got anything to compare it with.

Is it worth switching to 'super', or filling up with Optimax once a month - any thoughts?




Migration info. Legacy thread was 13790
 
I use nothing but super or optimax... the car runs great on the stuff!

Migration info. Legacy thread was 13792
 
Likewise I only use Sheel Optimax or Super plus unleaded, the theory being it burns better and keeps the chambers in tip top condition (Evo mag did a test on this a while back). I do notice the different in mid range pull.

Migration info. Legacy thread was 13793
 
isnt the 993 designed to run on 98 ron fuels - i think only optimax is 98 ron unleadeed - reg unleaded is 96 and the other 'high performance' unleaded fuels i've seen are 97 ron. Running at a lower octane rating will cause the car to reatrd the ignition to prevent knocking or pre-ingnition i believe - i'm sure someone else can confirm or not!

Migration info. Legacy thread was 13796
 
The anti-knock sensor will retard the timing to prevent pinking when 95RON fuel is used. Thus when Optimax is used the engine feels much better.

Migration info. Legacy thread was 13801
 
Optimax is supposed to be 98RON but it's not guaranteed at that - only 95RON. Only SuperUnleaded is guaranteed to be 97RON as advertised.

Migration info. Legacy thread was 13803
 
From shell.co.uk

<Sorry previous link not available after migration>
1.gif



Shell Optimax has the highest octane specification of any petrol available on UK forecourts. It is greater than 98 Research Octane Number (RON).

So thats false advertising if it aint!





Migration info. Legacy thread was 13810
 
I remmember reading somewhere that other superunleaded use different chemicals from Optimax to boost the octane, and there was a claim that it may even cause long term damage to some engine. I don't know how true that is or whether there's any evidence to back that up. I never use anything other than Optimax for my 993 since Optimax was introduced, and the car has been running great!

Migration info. Legacy thread was 13819
 
I'll try to dig out my evidence - it was researched thoroughly on my Calibra forums. Optimax was found to be the weakest..

.. with that said, I use it regularly because I'm happy to believe the hype and it DOES appear to make a difference. It certainly isn't hurting the car!

Migration info. Legacy thread was 13820
 
I work in the oil industry for one of the major players and I'd take their RON values with a pinch of salt. As for my 993, I run it on regular unleaded with no problems at all.

Dunc


Migration info. Legacy thread was 13821
 
This was debated to death on Scoobynet as the Jap imports are designed to run on 100RON fuel. IIRC Optimax is normal 95RON with and additive which degrades over time, therefore Optimax could be anywhere above 95RON.

There wasn't a definative answer but the general consensus was Optimax is good and cars run a bit better than on normal 95RON. The other thing that struck me was the view towards supermarket fuel, it wasn't as purified as Shell/BP.

Phil


Migration info. Legacy thread was 13860
 
One thing that stuck in my mind from the Optimax debate on Scoobynet (or maybe it was the IWOC Impreza list) was that someone talked to a techie at Shell and was told that the typical rating of Optimax was 98.6 RON, hence the "greater than 98 RON" claim.

Migration info. Legacy thread was 13879
 
You must log in or register to reply here.

Similar threads

D
Stalling when warmed up and extended cranking time to restart
Replies
14
Views
1K
daviesjp
D
infrasilver
Rough running and stalling. ABS/PSM lights. NOT MAF?
Replies
5
Views
699
Alex
Alex
Alex
Steve Wright's Serious Moddin' - Cabriolet rear plastic window demister.
Replies
5
Views
643
½cwt
Â
911UK
Former GP F1 driver Nick Heidfeld and his 959 Sport
Replies
1
Views
769
DRZ911
DRZ911
Porsche News
Porsche mourns the loss of Herbert Linge
Replies
0
Views
308
Porsche News
Porsche News
Porsche News
The new 630bhp all-electric Porsche Macan
Replies
14
Views
1K
jonttt
jonttt
A
Yet Another 993 RS Evocation Project ;-)
2
Replies
20
Views
2K
chucknorris
C
Specialist in Porsche car sales

Latest posts

New Threads

Porsche Model Range

Porsche 911

Porsche 992: 2018- Porsche 992: 2018- Porsche 991: 2011-2019 Porsche 991: 2011-2019 Porsche 997: 2004-2012 Porsche 997: 2004-2012 Porsche 996: 1997-2005 Porsche 996: 1997-2005 Porsche 993: 1993-1998 Porsche 993: 1993-1998 Porsche 964: 1989-1993 Porsche 964: 1989-1993 Porsche Carrera 3.2: 1983-1989 Porsche Carrera 3.2: 1983-1989 Porsche Carrera SC: 1977-1983 Porsche Carrera SC: 1977-1983 Porsche 930 Turbo: 1975-1989 Porsche 930 Turbo: 1975-1989 Porsche Early 911: 1964-1977 Porsche Early 911: 1964-1977

Porsche Hypercars

Porsche 918 Spyder Porsche 918 Spyder Porsche Carrera GT Porsche Carrera GT Porsche GT1 Porsche GT1 Porsche 959 Porsche 959

Other Current Porsche Model

Porsche Taycan : (2019-0%) Porsche Taycan : (2019-0%) Porsche Macan : 2013- Porsche Macan : 2013- Porsche Panamera : 2009- Porsche Panamera : 2009- Porsche Cayman: 2005- Porsche Cayman: 2005- Porsche Cayenne: 2003- Porsche Cayenne: 2003- Porsche Boxster: 1997- Porsche Boxster: 1997-

Porsche Legacy Models

Porsche 928 Porsche 928 Porsche 968 Porsche 968 Porsche 944 Porsche 944 Porsche 924 Porsche 924 Porsche 914 Porsche 914 Porsche 912 Porsche 912 Porsche 904 Porsche 904 Porsche 550 Porsche 550 Porsche 356 Speedster Porsche 356 Speedster Porsche 356 Porsche 356

Forum statistics

Threads
124,554
Messages
1,441,465
Members
48,967
Latest member
Max V

porsche insurance porsche parts porsche sales porsche car sales porsche for sale
porsche classic sales porsche tuning porsche sold porsche specialist porsche engine rebuilds porsche driver training porsche car sales porsche exhausts

Community platform by XenForo® © 2010-2024 XenForo Ltd. XenForo theme by xenfocus

www.911uk.com @Porsche911UK THE DEFINITIVE PORSCHE FORUM Copyright © 911UK 2002-2024 All rights reserved.

911uk.com is not associated and is wholly independent of Porsche Automobil Holdings SE, Dr. Ing.h.c.F.Porsche AG, Porsche Cars GB, its subsidiaries and offical Porsche centres. Any word, phrase or graphic that in any way resembles anything to do with the Porsche name or organisation are registered trademarks of Porsche Automobil Holdings SE and Dr. Ing.h.c.F. Porsche AG.

Back
Top