5.7 HEMI & 87 octane gas - Page 5

300C_Chris · 03-03-2008, 07:10 PM

The SRT design has the 5.7L engine.

When i had my 300C 5.7L. I was running the 93 octane with the SC tuner and when i would return it to stock for service visits i noticed the engine ran way better with the 93 and the stock tune. Try it , you'll see what i mean.

**LSCto300C** · 03-03-2008, 11:01 PM

How would the 300C react to 85.5 octane??
That's what I put in my current cars with no bad side effects, but since neither of my cars is a 300c yet I'm not sure how it would react...

bigsnake · 03-04-2008, 09:52 AM

Clarkkent, perhaps you should go back and read your first post! The SRT8 = 6.1
SRT Design = 5.7 with MDS! It's wise to gain some knowledge about a vehicle before pontification! Reminds me of your comment of the T Stat not doing anything for the car!

chuckkent · 03-04-2008, 10:14 AM

There are so many versions of the 300 its impossible to know them all. I was asking a question about a SRT Design and making a comment on the 6.1L.....so relax...... It would be my guess that a 5.7 would run just fine on 85 octane fuel as mine hasn't complained about any regular fuel I have put in it so far.......

ricardo · 03-04-2008, 10:22 AM

I tried 87 thinking that computer will be able to make adjustments, but on the second tank of 87, check engine light came on. I switched to 91 and the light went off after about one tank. I think the recommended 89 is the best.

Husker · 03-04-2008, 11:41 AM

LOL..so the 6.1 doesn't get good mileage huh...

You might want to rethink that

chuckkent · 03-04-2008, 02:30 PM

The Chrysler SRT Design is a 3L V6 diesel sold in UK. Now I'm really confused....

chuckkent · 03-04-2008, 02:32 PM

ricardo, I think something else was going on with your vehicle. 87 should be just fine....maybe the gas cap wasn't tight?????

HKS · 03-04-2008, 04:13 PM

85 octane is available in the western states like Utah and I have seen it at WalMart in IOWA. I will put in 87 but I stay away from 85. I do not want to take a chance of damaging the engine which would happen when you needed to floor it passing cars on a two lane highway.

HKS

Quote:

Originally Posted by LSCto300C

How would the 300C react to 85.5 octane??
That's what I put in my current cars with no bad side effects, but since neither of my cars is a 300c yet I'm not sure how it would react...

Husker · 03-04-2008, 06:14 PM

Quote:

Originally Posted by HKS

85 octane is available in the western states like Utah and I have seen it at WalMart in IOWA. I will put in 87 but I stay away from 85. I do not want to take a chance of damaging the engine which would happen when you needed to floor it passing cars on a two lane highway.

HKS

Do you mean E85?? I have never seen 85 oct anywhere in Iowa/Nebraska