[kangol99]

Can someone please once and for all tell me what the best octane and oil is to use? I live in michigan and will be driving my 300c all year round.....any suggestions?

 

[Black Hemi]

I believe it is recommended to use minimum 89 octane fuel and 5W30 oil. I got that by just doing a search.

-Chris

 

[Redman]

89 is recommended.
Heard we should be using 5W20, no?

 

[FOAMAVEN]

I believe it is recommended to use minimum 89 octane fuel and 5W30 oil. I got that by just doing a search.

-Chris

He said a 300C so that would be 5W-20 oil. 5W-30 whould be a problem for the MDS.

 

[Black Hemi]

whoops, typo 5W20 is what my mind typed . . . not my fingers

 

[slk320]

5W20 - Royal Purple, RedLine or Mobile1 synthetics

89 from a reputable gas station (Chevron, Shell, etc)

 

[JPB68]

my dealer said not to use synthetic. Only in the crossfire

 

[LegalShield]

my dealer said not to use synthetic. Only in the crossfire

Its not necessary to use synthetic motor oil in the 300C. It is required in the Crossfire. I chose to use synthetic because I live in a seasonal environment were temps range from 20's-30's in winter to 90's-100's in summer. So synthetics are a great choice. There is an entire thread dedicated to the syntetic advantage, check it out.

 

[catchMEifUcan]

89 octane

89 octane!

I ran 92 (shell) for a couple months and the engine would hestitate sometimes when "stepping on it."

Changing back to 89 (after about a month - ~1,000 miles)... the hesistion left and it felt better (or maybe it was that I past 5,000 miles? ).

Either way, I gained about 2 MPG (now run in the 20-22 range with mixed highway and city driving) after changing back.

 

[II kings 9:20]

my dealer said not to use synthetic. Only in the crossfire

Your dealer is a complete idiot.

 

[II kings 9:20]

The manual calls for 89 octane, not a minimum to suggest 93 is better, it calls for 89 only and months ago someone posted ingo from DC that above 89 could be detrimental. 5w20 ONLY, your choice on synthetic but it is clearly superior.

 

[Hemilover]

Just had a oil change this week and asked service manager about synthetic oil and he said its not recommended in the "C" and don't use it. So I didn't!

 

[CottyGee]

Just had a oil change this week and asked service manager about synthetic oil and he said its not recommended in the "C" and don't use it. So I didn't!

Why?? Why is the question. Since it is a proven FACT that synthetic oil is VASTLY SUPERIOR, why should one not use it???

Without any information to back up the claim, the claim itself is of no use. Not trying to be argumentative here - just pointing out the need for the info...

 

[Hemilover]

I agree about with you about synthetic oil, but he said not to use it because its not recommended in the manual so I didn't want to give them any leverage to come back at me later and say I wasn't using the recommended oil. Chevy screwed me this way when the camshaft went on my 1976 Impala.305. So I guess I'm just covering my ass.

 

[cirob]

Hemilover I am worried about your dealer page 294 in your owners manual
you may use synthetic engine oils provided that the recommended oil quality requirements are met etc. use 5w20 for hemi. All motor oils meet or exceed manufacturer specs. They do not recommend oil additives.

 

[Hemilover]

Thanks Cirob I will point that out to him next time. I guess the sooner you change to Synthetic oil the better on a new engine thats why I wanted it this time (3rd oil change) but went with his advice. Thats why this forum is so good!

 

[CottyGee]

I ran dino for the first 500, then for an additional 1,000, then at the 3rd oil change (1,500 miles) switched to synthetic (Valvoline 5W20).

 

[II kings 9:20]

There is tons of info in the syn oil sticky, you guys are correct the manual endorses the use of syn or dino as long as it is 5w20. I switched to syn at 1875 and completed my third change two days ago at 6K, I'll get on a 6K schedule now. I'll say it again, your dealer is an idiot.

 

[LWOOD]

I'll get on a 6K schedule now. I'll say it again, your dealer is an idiot.

So There!