Should I be running 98 octane fuel every fill up?

[ballbaggins]

does anyone else think that the Petrol test - Today Tonight Adelaide is bs... they dont really get into details and the results dont make sense in my opinion.

 

[Husky]

I get around 50Km extra out of 50L BP98 vs regular 91. Not much, but for the extra $7.50 a fill I don't mind running the good stuff. I do plan to get it tuned for premium one day.

 

[Super_Low 91]

I don't really have much to add this debate as every car iv owned has been tuned for 98 especially with my current car being supercharged, If i run anything less it doesn't run properly at all. I personally agree with what allot of people are saying if the car is tuned for it then use 98 but if it isn't then you wont get the full benefits from using 98 an you should stick with 95 or 91.

 

[s_ikari2015]

have a gander at the American fuel standards, where these engines come from.

 

[IRON8]

i just started using 91 in my ute and it runs so much better than on 98 !! bizzar, has a little less punch off the mark but has a noticably longer rev range and idles "almost" smoothish... on 98 it shakes quite bad at idle like compression is down in one cylender. id like to know the science behind that but im happy it prefers the cheap ****

 

[B-Man]

i found bp summer mix is crap in the karts

 

[sleek_vp]

you could say that but i dont think so I have my regular shell servo down the road and ive used both their 91 and 98 and there is a huge difference 98 is a **** load better fuel never going 91 again

 

[sleek_vp]

run both my cars (vs and vz v6) on 98 and nothing lower, used to run 91 in both until one day the vz started missing lots and with my vs engine running was average especially at idle and piss poor fuel economy changed to 98 and engine runs great and economy well i thought my fuel gauge was faulty for a week there, bit more expensive but totally worth it, i thought it was all a gimmick (some of the 98 radio adverts are a rort) until both my cars run 100% better, shell or bp 98 ftw and btw ethanol can take a hike worst fuel quality ever

 

[terry1971197]

Any octane level 91 or above as advised in section 5 of your VZ users manual should be ok to use.

It is likely that any significant improvement in performance by using a higher octane fuel is due to a problem with the Engine Management System.
You probably need to take your car to a specialist.
If your vehicle has ever had an overheating problem it would be prudent to suspect a problem with the ECU as it is bolted to the front of the engine.
Overheating can have a permanent detrimental effect on the complex algorithms theses devices produce.

 

[taslucas]

I've got another question regarding the engine being tuned for 98: as I've recently purchased the vehicle (99 ls1) I have no idea what it may have been tuned for and I've been unsuccessful in finding that out. It has an otr, mafless tune, cam, Higgins heads etc and was dyno'd at 284 rwkw so would it be safe to say it is tuned for 98?
I ran 98 for a few weeks then went to 95 (mainly because of availability down here) and I may be imagining it but it feels slightly more economical. I'm not concerned about economy but thought that might show the engine is running better.
But having said all that, Im still getting used to it so I may have nf idea what I'm talking about lol.