95 or 98 RON - the truth is out?

[dickbowyer]

I thought (and sales at cc told me) I need to use super unleaded 98 RON in my Duratec R400 but was interested to see that the Owners Handbook on the CC site Handbook pdf suggests ordinary unleaded. That will save a few bob if it makes no difference.

 

Dick

Superlight SV Duratec R400 Arch Inside 😬

[myothercarsa2cv]

Using 95 probably won't cause knocking.

 

But it's not just the octane that is different between the two fuels, it'll be everything else that goes in to the blend too. Using 95 may save you money at the pump, but 98 may be more efficient in your engine (higher mpg) and may improve longevity of the fuelling system (less carp to bung up the injectors etc. reducing maintenance).

 

Up to you what you use, I tend to use whatever is at the pump personally!

 

John

_________________________

 

Bugsy: '82 2cv6 (Gearbox imploded )

Talloulah: '08 1.6K Classic (Tarnishing nicely ☹️)

[Angus]

The advice from Caterham on this when I completed my R400D build earlier this year was that 95 was OK but the occasional fill up with 98 was good.

[Pat the Plumber]

Richard,

as you are aware of the wonderful 21/22mpg that we're getting.

i'd always filled mine up with normal unleaded, until i did the track day at Oulton park.

on the journey up the motorway at a steady speed, i returned nearly 28mpg. unheard of.

when i first picked the car up, slower speeds on the M40 and got less return. probably the engine was tight.

 

i only every put 98Shell in, as a piece of mind, and a couple more miles.

 

R400

[sjmmarsh]

I realised the same thing about my CSR 260. I will still use 98, but it is good to know that I can put 95 in if I can't find the full-fat fuel. When touring it is surprising how many garages don't stock it.

 

Steve

[Slipper man]

I was told by Minister thay my K series R500 was mapped for 95 RON. I would be amazed if the later cars needed 98. Having said that on a circuit I always use 98 because an extra safety margin cannot do any harm

[Nifty]

That's interesting Keith because I was told my R400 was mapped for 98 RON ... it is an ex-race engine, perhaps race and road were mapped for different octanes ?

 

 

 

 

 

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Keep off the straight and narrow 😬

 

Edited by - Nifty on 7 Dec 2008 08:59:37

[RiF]

5 years on 95 with my Raceline Duratec

Tried 98 and it did not like it as much.

 

RiF Driving one of the first Duratec 7, and building CA07BON for Henrietta 😬 😬 😬.for pictures of 7 and carbon andCA07BON

[Nifty]

Ford ... huh ❗ ❗

 

 

 

 

*tongue*

 

 

 

 

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Keep off the straight and narrow 😬