The Jaguar service guy said I could get away with using '87 while driving in the city. I usually only use '91 but might just give the '87 a try with '91 being $4.00/gallon now.

 

Unless it would state that you should only use premium ,regular octane should be OK too. I use premium but I have not got any problem with the regular either

 

98 octane ONLY, is there any other??

$1.86/ltr today, fair dinkum.

 

My cars are sluggish on 87 octane. This morning I paid $3.50 per a gallon of 93! It hurt, but I had to do it.

 

In Europe we envy your low fuel prices!

I tend to fill up with Super unleaded since the car seems to run slightly better. At current exchange rates this is currently $2.24 a litre - or $8.48 for 1 US gallon. Standard unleaded is slightly cheaper.

 

It's $3.75-$4.00 a gallon for 91 in San Diego. They don't allow 93 or 95 octane at regular gas stations in CA. You can get 100 octane unleaded racing gas at specialty stations but it's $8.00+ a gallon.

 

deleted, wrong forum.

 

You learn something new everyday! That's ridiculous!

 

I still use super still, the difference in price for me is about 4 bucks per fill up. If it gets much more expencive I will use regular with octane additive I can get for 3 bucks a bottle.

 

Does octane additive really work. I plan on continuing to use high test? I figure it is worth 7 or 8 bucks a fill up to be safe.

 

Most of them are just snake oil. Those that do work cost more per tankful to boost octane than just buying high octane gas in the first place. The labels on the bottle are very clever by stating how many 'points' the product will increase octane. By 'points', they mean 0.1 not 1.0.

Save your money.

 

I just filled up at 1.30/ltr last night and I thought that was crazy, I guess we aren't the only ones getting nailed. I'm on the highway most of the time so I guess I will soak it up

 

Ahh learn something new every day, did some reading on on it and found that it is usually Toluene/ Xylene that is in these boosters. Now that stuff is pretty damn cheap by the gallon, but what happens when you ' homemake' some of this with the classic toluene, mineral spirit, atf fluid mix and put enough in the tank to raise the octane a few integers? Is it going to slowly eat the engine alive?

 

I use the 91. Somebody wasn't happy with the old system and so they came up with a new one which changed the numbers.

Watch octane boosters. Some contain lead and say bye-bye O2 sensor.

If you have a later model car, it will have "knock sensors." When the low octane gas pings, the ECM changes the spark advance and cam timing. You may think that you have 11 to 1 compression ratio, but delay the closing of the intake valve and it is the same as having 7 to 1. Watch what you do with supercharged engines.

 

Has anyone ever filled an entire tank up with 100 octane UNLEADED?

That goes for $8.00-$8.99 a gallon in San Diego. I might try 4 gallons for fun.

 

You'll gain nothing but a lighter wallet. Octane ratings in excess of the engine's need, which is identical to or lower than the manufacturer's recommendation, is just pure waste.