Fuel octant level?

[Domenic]

Reading the general forum i saw the american 300c's have a recommended 87 octane fuel from chrysler. How does this translate to us in australia, as far as i know our fuel only comes in 91, 95 and 98 octane unleaded. Do they use a different system of rating their fuel over in the states or do they in general just have inferior fuel to us? What octane fuel should we be using in our 300c's over here? And any idea what rating we should be expected to use in the srt8's???

[BobF]

Originally Posted by Domenic

Reading the general forum i saw the american 300c's have a recommended 87 octane fuel from chrysler. How does this translate to us in australia, as far as i know our fuel only comes in 91, 95 and 98 octane unleaded. Do they use a different system of rating their fuel over in the states or do they in general just have inferior fuel to us? What octane fuel should we be using in our 300c's over here? And any idea what rating we should be expected to use in the srt8's???

Try this site:

http://www.madabout-kitcars.com/kitcar/kb.php?aid=124

[GoofyTimL]

Actually the 300C (V8 Hemi) has a recommendation of 89 octane in the US. However, many folks such as myself have found no notable difference in performance or fuel economy with 87 octane. However, some have reported that performance has been noticeably poorer using higher than recommended juice.

[snoopdolks]

There was a massive thread on this somewhere on the forum, most of which I read through at one point.

The owners manual of the Aussie delivered 300C suggests "designed to provide optimal..blah...blah...using high quality gasoline with a minimum research octane rating of 95." It goes on to say that we can use 91RON if 95RON is unavailable but performance will probably suffer.

I think the summary position on the forum was, in the US they recommend the mid-rated fuel, ie. RON89. In Australia we have 3 variants as well, which you point out are all quoted above the top quality US fuel. It has been suggested that this is due to a slightly different formula in the US or regulation about the number used to represent the RON and in fact it is the same stuff at the same grades but the number reduced by about 2 in each instance. Therefore, I'm using "mid-strength" 95RON (Premium but not 97 Optimax etc) in my 300C Hemi.

[GoofyTimL]

Someday or year... we're going to come down under for a visit to New Zealand and Australia. I hope I can rent a 300C for the road touring.

[Hemi57]

GoofyTimL, you will be made welcome down here but I doubt you will be able to rent a 300C, V6 or V8. You never know if a boutique Car rental company might get one but it will cost an arm and a leg.

On the Octane vs RON discussion. I don't know the conversion formula but Chrysler advised me when I raised the "issue" of them recommending 95 RON that it was equivalent to 89 Octane in the US.

Some old threads suggest that a higher than recommended Octane with mess with the MDS so don't do it.