Octane rating

A couple of queries re fuel:

Is Shell Optimax suitable as a replacement for leaded petrol

Does it give better mpg than 2 star (in a suitable engine)

TIA

Reply to
sa3214
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As far as octane rating is concerned, yes. As far as valve seat protection is concerned, no.

Yes, but I doubt if it justifies the extra cost over normal unleaded. N.B. the star ratings apply to leaded petrol.

Reply to
Richard Porter

No. Unless you're valve seats can already handle unleaded. The best answer for a car which can't use unleaded is Tetraboost - pretty much the only additive which when added to 95 Octane Unleaded will give you 97 Octane Leaded (i.e. it adds the Lead).

Creating your own Leaded petrol is perhaps a little dubious but it's legal and Tetraboost has recently been approved by the FBHVC.

Where do you get 2 star this century?

Reply to
Doug

Perhaps he is asking if it is equal to *what* 2 star was,,,, ;-)

Reply to
all at home

Shell Optimax and Castrol Valve Master are a good combination. Higher Octane from the optimax will help the engine run better, and valve master should help the valveseats. Or an altenative to Castrol Valvemaster is Millers Superblend zero lead 2000.

Reply to
Skatiechik

Does this mean that if you add Tetraboost to Optimax you get 100 octane? Or doesn't the chemistry work like that?

Jim

Reply to
Jim Warren

2.5 PI Jim?? ;-)) I asked this question a while back, can't remember getting an answer but I'm sure it's a simple arithmetic situation, given that dosing up with "homebrew" mixes made of lacquer thinners and the like will apparently keep adding those octane points!

Anyone?

I'm tempted to add Millers VSP Octane Boost and Lead Replacement to Optimax (98.5ron) to try to dial in some more advance. At 20mpg there's little point to me counting the pennies considering the limited mileage I do (less than

3000 per year).
Reply to
DocDelete

Yes, that's me :-)

The PI is resting until they stop putting salt on the roads, but if I can find a supplier of Tetraboost in the mean time, I think it is worth a try. Google here I come!

I'm getting about 24mpg and am doing about 2500 miles a year in the PI, so I have got even less to lose.

Jim

Reply to
Jim Warren

Through the magic of Google, I can answer my own question. See

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you will find that the answer is Yes. Jim

Reply to
Jim Warren

I'm using mine, scrubbed the kerb the other day trying to avoid a gritter. My other transport is poorly with cylinder head removed right now so the PI has had to bear the winter brunt. I've enjoyed every minute aside from the micro brown spots appearing on the thin old original paintwork. :-(

24mpg? What sort of driving? I get 18-20 on my daily two-commute of 10 miles total - urban with a short blast on a dual carriageway.

-- Ken Davidson

snipped-for-privacy@removehotmail.com remove remove to email

Reply to
DocDelete

I'm retired, so I rarely travel in the rush hour in it. And most of my journeys are sightseeing or visiting relatives, so over 50 miles and mostly motorways or A roads.

I've got a 2000 for local shopping trips and that sort of journey only gives me 18mpg. It does the winter journeys too - and collects the rust from the salt :-(

Jim

Reply to
Jim Warren

Why not just buy proper leaded 5 star, if your mileages are low and pre-planned??

MrCheerful

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Reply to
MrCheerful

You know where they can buy it ??

Reply to
ROBIN

Leaded petrol which is the equivalent octane rating to 5 star (according to the makers) is available all over the country.

A list by county is available here:

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HTH MrCheerful

Reply to
MrCheerful

See

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.

Reply to
Richard Porter

LOL the nearest one to me is 12 miles away,,, its a bit of a journey just to get petrol

Reply to
ROBIN

Surely you go out to go somewhere, not just to buy petrol?

MrCheerful

Reply to
MrCheerful

yes but not always in the direction of the only 2 gararges that are withing

50+ miles of me that sell 5star....
Reply to
ROBIN

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