Sluggish performance and 89 octane gas

[II kings 9:20]

What, no Amarada Hess in DC, you are getting robbed, I put money on my Wal Mart gift card and save 3 cents/gallon pay at the pump, wohoo.

[scandaloustrick]

91-93 octane as far as the station goes in downtown chicago...
Most the time I use shell V-power...

[turbohips]

never had a problem with 89 Arco, Chevron, Shell, Mobil, and USA gas

[steve 300c]

93 octane you guys are so lucky all we get is 87 89 91
but as far as the 300c, mine was started on 91 but after reading the manual later found 91 0ctane wasnt recomended however after switching found the mileage improve 10fold. maybe its cause the engine was brand new or it was the fuel type but after 7000 km all is well and never better on the Shell bronze 87 octane.

[II kings 9:20]

Originally Posted by steve 300c

93 octane you guys are so lucky all we get is 87 89 91
but as far as the 300c, mine was started on 91 but after reading the manual later found 91 0ctane wasnt recomended however after switching found the mileage improve 10fold. maybe its cause the engine was brand new or it was the fuel type but after 7000 km all is well and never better on the Shell bronze 87 octane.

89 is recommended for US cars my mpg dropped from 15+ to 12 with the onset of cold weather and more city driving. 4400 miles thus far

[CAS]

Originally Posted by motrhed87

Hey everyone,

They called the Chrylser tech line and they said that I should use at least 91 octane gas, not 89 as stated in the owners manual.
Thanks!

Octane rating will only be relevant if you are experiencing pre-ignition (engine knock) which should be as noticeable as the sluggishness if it is the cause of such. You might also experience elevated engine temperature as well if this is at play. Gas companies have tried to boost profits for years by encouraging the public to buy gas with higher octane ratings than their cars' requirements.

A fuel's octane rating is only a measure of its ability to resist pre-ignition, and will not boost engine performance outside of that element. Unless you have created a situation (i.e. engine mods that increase compression ratio, or forced air induction) that increases your engines propensity for pre-ignition, you are merely wasting your hard earned dollars unnecessarily, (and boosting oil company profits.)

[wild bill]

6,ooo miles on mine nothing but 89 octane ,like a rocket ship.

[II kings 9:20]

CAS nailed it, my dad's old Grand Marquis (a true dad car) pinged like crazy, I practically had to force him to try 93 and problem cured with noticable improvement in acceleration. Now, we changed the plugs and went back to 87 and ran as well as with 93 no ping and very smooth.

[steve 300c]

Still running 87 octane and no sh@# 40$ Cdn and i went 724km.
maybe i got a lucky car, but no horsepower losses here.

[Dxun]

Originally Posted by motrhed87

Hey everyone,

I have a 300C with about 4500 miles. I feel that the car has become quite sluggish over the last 1,000 miles or so. I brought it into my 5 star Chrysler for a check up. The tech said that he ran it with the diagnostic equipment attached and that the computer said the gas was not burning properly but did not really have an answer as to why this is happening. They called the Chrylser tech line and they said that I should use at least 91 octane gas, not 89 as stated in the owners manual. They also said that an addendum to the manual is scheduled to be sent out stating this as well. I have read the other posts regarding octane rating and everyone else seems to be satisfied with their performance on 89. I was just wondering if anyone else was experiencing similar sluggish performance or had any ideas as to what the problem could be.

Thanks!

I have similar problems with my 300 as well. It seems as if when the car is cool it pulls like an animal, and as i drive it seems to lose power and become sluggish. I have been using 91 octane fuel from the start and have tried quite a few brands and noticed the same problem. Not sure what the hell to do at this point but i'll be dropping it off today and making a pretty big stink about it. Installed the AirRaid cold air intake system and i was hoping that with some luck it would run cooler and solve my problem but no luck there either.