Yep, I think I will stay with BP ultimate then

g-day guys n gals.Being in the rallying scene we have had a few test reports in the cams magazines of late .One that was very interesting was a comparison between Methanol "oh what a lovely smell that is" and BP ultimate with a certain octane booster,all of this was done on a race engine "ie big cam, high compression open exhaust".and guess what the BP ultimate out did the Methanol. Apparantly this was because the Ultimate could handle more ignition advance and can suposedly handle compression up to 12.0 to 1. I will try and find the article so i can let u all know which aditive it is. You may find that you wont really feel any difference with a 5.0 as without a nock sensor the ignition would have to be manually advanced, Where with the 4.0 the ecu would gradually advance by itself while re-learning fuel air and ignition ratios

ultimate all the way, haven't found a bad batch yet. optimax is only good in barrels (toluene, used to raise the octane, cannot evaporate from a barrel like it can from the compulsory vents in servo tanks). my 5.0L pings on anything but ultimate or lpg! (not tried vortex yet, mobil 8000 only under very high heat & load).

You might find that your no longer on Shell's Christmas card list after that statement.
I heard only some small time servo's were using Toluene to increase supply and profit to any fuel...

That's ammusing considering that Mobil buy their Premium UL from Shell (Optimax) and then rename it Synergy 8000!

I haven't touched Mobil since they stuffed up all the AVGAS. I've noticed no difference b/n BP and Shell.

Max power is produced when peak cylinder pressure is acheived @ about 15 degrees after TDC. If you're timing is such and you're not pining, then ANY change in ignition timing reduces power.... Was that engine boosted?

Last edited by unclewoja on Mon Feb 07, 2005 10:07 am, edited 1 time in total.

I have been looking for some opinion on the best fuel for a while...

It seems to me that most seem to favour BP Ultimate now - it was only a few years ago that Optimax was supposed to be the best.

I think the "blind" test on the wife (see another post above) is a great idea, so i'll try it !!

Well after using this BP ULtimate stuff now for nearly 3 weeks now, I have noticed I dont get as good Fuel Mileage as I did with Optimax. But power levels seem just as good. If nothing else I also still have a nice "purring Idle" with the Ultimate. Which probably cancels out the lower Fuel Mileage. That hesitating idle use to give me the s**t heaps

Only problem with the blind test with the wife was is was showing up the differences b/n cheap regular and Ultimate... not Optimax and Ultimate.. .and that's what this thread is discussing.

We all know that just about any PULP will be better than ULP

Wow, sounds like you guys have got it made... all those different fuels to choose from...

I live in WA, and work for Shell, however we don't get optimax over here. I don't think we get that Mobil 8000 either. Over the past two years, I have been exclusivly using Shell PULP, as have my family (Probably due to my 20c/l staff discount-- I usually get PULP below 80c/l)

Having said that, despite my large discount, I must admit that i have fallen victom to BP's recent advertising BOOM!! Any one in WA will know what i'm talking about. Not sure if the same thing happened in the eastern sates but BP has been pushing Ultimate in a very big way. Anyway back to me falling victom, so i was at work, reading a wheels mag during a quiet period and discovered a BP ad. It went on and on about how good Ultimate is for your motor, " out perform the others" etc... and after a few moments of reading, my mind was made up, I was going to forgo my huge discount for Ultimate. My tank is now down to about 1/3 so i'll have to wait a bit longer before i get it. I'll re-post with my opinion.

I also wanted to ask, will adding a octain boost to Ultimate increase its RON above 98 or is it ineffective with fuels that already have a high RON rating??

wow sorry for the rant!!!

Cheers,

Kenezevic.

Contrary to popular belief 98 RON isn't high at all, so adding octane booster will boost your octane levels.

In a N/A engine it makes bugger all difference. You might get an extra 1 or 2 kW out if it. When you start using it in a boosted engine, you can run higer boost and more ignition advance and get a hell of a lot more than 1 or 2 extra kW.

100/130 AVGAS has RON of 130. It also goes through much more refining than other petrols and it is the best thing you could possibly put in your car.

Only problem is it's around $1.30/L atm and illegal to buy for road use, BUT, if you go down to your local airstrip (not a major airport, just a little one with a little strip and 3 or 4 planes) with a 20L drum, you can buy AVGAS for your "ultra-light aircraft" and that's perfectally legal. They don't need to know it's going in your car! It's also perfectly ok to mix it with other petrols.

Yeah, my mate and i have considered using Avgas in our cars, since we both are studying aviation and both fly on a regular basis. Maybe i can jig something with the boys down at Shell or BP. would be nice though, 130 RON!!

Cheers,

Kenezevic.

Nah. They won't do it. They have to account for every drop that comes in and goes out.

A few mates of mine drained 80L of AVGAS from another flying school's plane a few years back and put that in their cars

my car don't like the bp ultimate,,, it loves the mobil syn 8000

I use the 95RON Caltex Vortex. But now Vortex98 is available in the ACT (@ 116.9cpl !) I'll give it a try.