RV8s: Do you run on super unleaded or 95 RON?

[Chris71]

Do the standard Rover V8 Tivs actually need to run on super unleaded?

So far I've always put Optimax in my Chimaera 500, but at - realistically - something less than 300bhp from a thumping great 5-litre V8 do you really need the detonation resistance of a high octane fuel?

[Oggs]

95 in mine

[Mr MoJo]

Super for mine, 97ron or above (99% of the time its V-Power) as recommended in the handbook.

[tubbystu]

Try it without

Mine loves Optimax V power, is OK with Esso & Texaco Super and just hates BP Super.

It runs pretty poorly on straight unleaded on the occasions when nothing else has been available etc.

If it is set up for Super it needs Super and the same goes for straight unleaded as the ECU isn't an engine managment unit and is not particularly intelligent IIRC.

[Chris71]

Ironically, minutes after typing the opening post I went to fill mine up and there's a big sign on the filler cap saying 98 RON only. I calculated the resulting 20 minute (relatively sedate) drive cost me over a tenner. Looks like I'll have to cut down on my other vices...

[tivver500]

I've run my Griff 500 on 95 with a tank full of Super every 2nd, 3rd or 4th fill up.
This as recommended by Richard at Dulford Automotive. It's run well for the last 10 years.....

Chris
TVRCC RO

[Chris71]

tivver500 said:

I've run my Griff 500 on 95 with a tank full of Super every 2nd, 3rd or 4th fill up.
This as recommended by Richard at Dulford Automotive. It's run well for the last 10 years.....

Chris
TVRCC RO

That makes sense if- as I rather suspect - it's the additives they like rather than the higher octane rating as such.

Nobody's destroyed pistons or anything through detonation using regular 95 RON then?

[5.0ltr]

OK lets put my 4penneth into the hornets nest of 4* ... Vin ordinaire unleaded only in mine, and never missed a beat, plus on the cheap stuff `won` highest standard Griff at Growl rolling road.

[darkcat]

i run 99 when i can, 97 if thats all i can get, shell v-power is good.

runs like a bag of spanners on 95, its a 400HC, so seems to need that extra bit of BOOM.

[Podie]

Ran the Chimaera on 95, and the Griff (any early 500 HC)has had the same treatment. A respected TVR specialist advised me not to bother with super.

Ran the S on 97, but that was mapped for it.

Edited by Podie on Wednesday 5th January 22:15

[dnb]

320bhp and 95 RON. I've never really understood why a car producing less than 70bhp per litre should ever need SUL.

[Alexdaredevilz]

What ever the nearest unleaded

[Biggles101]

Only had it 3 weeks but so far 4 tanks of fuel all std 95 ron. Runs fine but will try 98 super at next fill up just for the comparison

[CHGRIFF]

Problem is 5 litre compression ratio being 10+, also engine build and performance is known to differ from due to hand machining, making detonation point a variable. Some 5 litres are difficult to map to full power without encroaching on detonation especially at summer 30+ temperatures. If you know your engine you will know if there is any sign of detonation. This is best found when accelerating at full power, coming of throttle then applying full throttle immediatly, this inciting detonation. Any sign of detonation retard the ignition. Problem is many drivers would not recognise the sound. If you want to be sure use only 97 octane for full power and throttle range. 95 works for many cars and can be used for general usage. If on track 97 everytime. PS dont test for detonation with a crash helmet on!

[Biggles101]

Is this similar to the "Pinking" sound when your timing was too far advanced, as I used to be constantly adjusting on my old Triumph Spitfire? Certainly not experienced anything like it so far on my 500...

Matt

[Timja]

I use 95

[Speedracer329]

Optimax for me all the time. My Chim has a 4.6 V8 Development engine, & on the drive home from purchase & with a dodgy fuel gauge I was forced to use 97 ron. Big mistake, kept cutting out, ran dog rough & took a LONG time to get home. Soon as I topped it up with Optimax it was sweet again.

[dnb]

CHGRIFF said:

Problem is many drivers would not recognise the sound.

It sounds a bit like a tin can half full of pins being violently shaken. The snag is that if you hear it over a TVR exhaust without the assistance of det cans, it's a little bit too late.

Incidentally, since doing the tuning work on my car, it seems much less willing to knock.

[Robatr0n]

Our 400 only ever has 98ron or 99ron.

Can't be doing it too much damage as it makes good power and runs well on it.

[CHGRIFF]

In the old skool, Pinking is the same as detonation. Just a different expression, I think.