i sorta stick with what has given me absolutely no probs for my 54 beetle - BP ultimate
i also run BP in my T4 and my bikes with the same trouble free motoring..
hope that helps..
I can't give scientific results, but I only have experience with both of them, shell vortex and caltex vortex (the 98 one) with the celica. as well
as BP ultimate of course.
The celica's distributor can be turned to adjust the timing, and by using the different octane rated petrols, i can retard and advance the engine
ignition to suit the petrol octane rating to get the most zip and zhrooommm factor out of it. From standard to high octane petrol at the bowzer, I can
tell noticeably the difference in this achievable factor by how easily i can slip a wheel.
My tops to shell 98. Nothing beats it. When i time the engine to suit, i take the car around for about 20 mins, pull ova a million times, adjust the
dissy a million times etc, feel it out, any pinging then i adjust for the pre-ignition, and feel it out till i have it right enough to get the most
push. it makes a huge difference tuning for the 98 octane compared to what u wouldhave for 91 or 95 octane fuel.
When i have it perfected after a while of pulling ova and feeling it out (I don't own a pro-tuning shop unfortunately so i can not do this any other
way), those settings that work prime for Shell vortex 98 can not be matched by caltex or BP 98 octane. With these settings the BP and Caltex just
ping, and require retarded timing cause they just can't keep up with it. Perfected timing, being that of which the engine timing is fully advanced
where the engine itself doesn't ping even under load)
This means that, although they are 98, 98 octane is suppose to be an average of the octane of the petrol. There could me heaps of carbon compounds of
95 octane and 100 octane in the fuel mixture, but this number, the '98' is just an average, supposably. It just seems that shell has more carbon
compounds in it closer to 98 and above, no matter which shell servo i go to. (yatala or meadowbrook)
The others just can't keep up with it. I believe I just don't get as much power out of Caltex and BP no matter what the rest say. I'm still yet to
try 100 octane petrol.
sorry though, thats all i can contribute to help, i don't know about the rest of ur questions. but that is the one i would give thumbs up to most (Shell vortex 98)
That would be Shell V-Power? Yeah, known before as Optimax!
Hmm, I find BP Ultimate best in my 1800 Bay.
I tried Caltex Vortex ('cause I had a Woolies voucher), and sometimes BP 95 Premium. Neither feels as good as BP Ultimate. Particularly with the
Caltex, I had the feeling that I needed more accelerator to go the same speed: in fact, I was struggling to do 95km/h. Normally she can get up to
115km/h+ (not that I drive it that way). HOWEVER, the Bus is kinda moody, so I will have to repeat the trials a few times on the same long trip (which
I do often and in very similar circumstances) in order to have confidence in the results. I managed to get just over 11litres per 100km on my last
440km round trip camping (country roads) with BP Ultimate; using Vortex I used more but haven't calculated it exactly.
Cheers, A.
Looks llike a very personal issue to me. Cheers
I only drink 100 octane ie. Shell V-Power racing (don't think there are any others?). Mmmmm ... YUMmy. Hic! Though my 'master' (yeah,
sure!) doesn't like Shell service stations.
I'll drink 98's if forced to, and they all seem much the same to me (Mobil S-8000, Shell V-Powr, BP Ult. or Caltex).
I hate 95!!! Pchyerrrkk !
I normally buy Shell 95 or higher...
I have also used Caltex
but I don't drive enough on the highway to notice any difference...
Many VW owners say their car likes this fuel better than the other...
but I don't have a preference as yet...
Lee