A lot has been said about the spirit, and the fact that our cars not having a knock sensor, can’t take advantage of it.
After a couple tanks of normal Unleaded (Esso and Sainsbury ) went back to Optimax and all I can say is WOW! the beast has a new life!
I know, it shouldn’t, and the cheaper fuel didn’t even make the engine pink (it used to, before the rebuild) so I thought it would be as good, but the difference is amazing.
Don’t know, maybe I’m just getting old or the stuff really works.
Mine definitely prefers it. However, I think the ignition timing was specifically mapped for it (Emerald).
BP 97 makes it kangaroo around town. Optimax it’s much better behaved. I’d never have believed it, but the difference is night & day.
Top end? Can’t tell the difference!
Is it just simply that it’s a cleaner fuel anyway?
There was a superb post on here (I think) from a fuel expert who said theres only Shell and Esso (made from Middle eastern crude)thats any good regardless of claimed octane rating
All the rest is crappy stuff from Eastern europe full of volatile additives and grit
Over simplified but thats what I remember?
Mine runs better on Optimax and I get more flames
I use optimax too, coz the shell garage is 300 yds away.
I’ve tried the expensive stuff (Optimax, BP Ultimate) and not noticed any difference at all.
However put in a bad batch of any petrol and the bugger won’t hold idle.
Has anyone read the fuel study in this month’s EVO?
They’ve tested 95 octanes optimax BP ultimate & a 105 octane racing fuel. Interesting reading…
I’ll stick to Ultimate from a busy petrol station.
Tim.
You’ve got an Emerald though right Uldis?
Yes, and the engine was mapped on Optimax.
I would have expected the thing to pink on cheap fuel, but it didn’t.
Can’t point the finger at what I felt was the problem, maybe slight loss of power? rough?
But going back to Optislop was very noticeable, much better, smoother, wanted to rev easier
well… yeah… if it’s mapped to Optimax you’d expect it run better on it than 95 RON.
(Infact, I wouldn’t use 95 RON on it if it was agressively mapped on 97/98 other than if you’re cruising on light throttle. Detonation is NOT your friend.)
I thought as part of the 190 upgrade, the ECU was mapped to 98 RON
I thought as part of the 190 upgrade, the ECU was mapped to 98 RON
Not sure, but I can vouch that if you don’t use Optimax, it will pink like fook under load, especially when hot!
In all honesty, the Lotus 190 map is pretty poor, & an Emerald ECU properly mapped will transform the car’s drivability around town/road driving
an Emerald ECU properly mapped will transform the car’s drivability around town/road driving
AMEN to that Brother!!!
Looked into the costs of upgrading to get over 200bhp (including an emerald) but �3.5k is just too expensive considering my medium term plans. An emerald on its own with remapping would cost �1k. So drivability will have to stay as is for a while.
My Bog standard 170 S1 much prefers Optimax…Pinks like Booogery on supermarket 95 so its Optimax when I can get it.
BTW what do they sell at Bedford and other circuits…
My baby goes quite well on it.
if it’s mapped to Optimax you’d expect it run better on it than 95 RON.
(Infact, I wouldn’t use 95 RON on it if it was agressively mapped on 97/98 other than if you’re cruising on light throttle. Detonation is NOT your friend.)
Well yes, in fact what I was thinking, detonation being the later stage of pinking.
But it didn’t even pink, so I thougt it should run well.And it kind of did, but the difference became only obvious wen I switched backto Optisludge, I found out only then what I was missing.