Super Unleaded
Discussion
Hi all,
I know this is a topic well treaded in the forum, but I was surprised to read recently that TVR recommend only 95 octane in the Tuscan, with 98 for race use.
Does the engine have the necessary bits in it to make use of higher octane stuff, or is there no benefit to it? I know the cerb red rose had a map for 98 but didn't know about the six.
apologies if this has been covered previously, my phone cant see the search feature on here!
james
I know this is a topic well treaded in the forum, but I was surprised to read recently that TVR recommend only 95 octane in the Tuscan, with 98 for race use.
Does the engine have the necessary bits in it to make use of higher octane stuff, or is there no benefit to it? I know the cerb red rose had a map for 98 but didn't know about the six.
apologies if this has been covered previously, my phone cant see the search feature on here!
james
No way was that old Buick engine designed with Mobil 1 in mind.
1 tank of fuel should last some of you a year, so not to worry :PI guess the key thing here is that if these engines don't have knock sensors in, then they'll be designed for one or the other.
ie. if Powers are doing their rebuilds with 98 in mind, then running it on 95 won't do it any favours, where other engines can compensate (even if they dont like it)
ie. if Powers are doing their rebuilds with 98 in mind, then running it on 95 won't do it any favours, where other engines can compensate (even if they dont like it)
My Mk1 2004 car has a factory sticker by the filler cap stating
"95 Octane for road use, 98 Octane for track"...or words to that affect.
The 98 Ron requirement was, I believe, to address the detonation tendency on the Sp6 engines at high load/revs and temp.
Hence the Le Mans cars having extra injectors in the airbox...Jason has one of the LM airboxes fitted to his Tuscan race car.
Nick
"95 Octane for road use, 98 Octane for track"...or words to that affect.
The 98 Ron requirement was, I believe, to address the detonation tendency on the Sp6 engines at high load/revs and temp.
Hence the Le Mans cars having extra injectors in the airbox...Jason has one of the LM airboxes fitted to his Tuscan race car.
Nick
This sounds so like the RV8 engine.
My 4 litre was equally happy on either. I started on 98, but after a PH thread I tried 95, couldn't tell the difference, so only used 98 after that for track days.
My 5 litre I was told by the engine builder (Rob) "95 for road use, 98 for track".
So I started off on 95, then with a nearly empty tank and about to travel to a rolling road session, I stuck 98 in (actually Tescos 99). Change was immediate. Car ran far better, accelerated better, cruised more smoothly.
So for RV8s it seems to be a case of what suits your particular car.
Is similar true of the Speed 6?
My 4 litre was equally happy on either. I started on 98, but after a PH thread I tried 95, couldn't tell the difference, so only used 98 after that for track days.
My 5 litre I was told by the engine builder (Rob) "95 for road use, 98 for track".
So I started off on 95, then with a nearly empty tank and about to travel to a rolling road session, I stuck 98 in (actually Tescos 99). Change was immediate. Car ran far better, accelerated better, cruised more smoothly.
So for RV8s it seems to be a case of what suits your particular car.
Is similar true of the Speed 6?
In response to some questions above,
Super unleaded 98 octane does prevent knocking in the engine. I certainly found my Tuscan S doesnt like 95. So always run V power or BP ultimate. I certainly cant feel the difference but i can tell she is happier with it. But I recon every single car is different..... as we all know!
The other question about fuel going off, that is also true. however i beleive modern fuel is very unlikely to go off in the time frames were talking about. When the fuel goes off it turns "gummy" however with modern addatives Ive never seen it recently.
Super unleaded 98 octane does prevent knocking in the engine. I certainly found my Tuscan S doesnt like 95. So always run V power or BP ultimate. I certainly cant feel the difference but i can tell she is happier with it. But I recon every single car is different..... as we all know!
The other question about fuel going off, that is also true. however i beleive modern fuel is very unlikely to go off in the time frames were talking about. When the fuel goes off it turns "gummy" however with modern addatives Ive never seen it recently.
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