Dodge Challenger Forum banner
1 - 20 of 24 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Ok... New RT owner. Sales idiot says "Regular Gas" (my area...that's 87). Owners manual says that's OK for the regular challenger. .. but to use 91 in a 5.7 Hemi. My choices here are 87, 89, 93.

What does everyone use ?
 

·
Registered
Joined
·
1,045 Posts
Ok... New RT owner. Sales idiot says "Regular Gas" (my area...that's 87). Owners manual says that's OK for the regular challenger. .. but to use 91 in a 5.7 Hemi. My choices here are 87, 89, 93.

What does everyone use ?
-----------------------------------------------------------------------------------------------

When I had my 5.7L-equipped R/T, I occasionally ran 87 octane gas without issue -however- I ran 89 octane more often than not. I figured I'd err on the side of potential increased performance and "better gas" in general.

Whereas the 89 octane cost me an 8-10 cent (per gallon) premium over 87, I believe I recovered that slight cost differential, easily, in increased mileage !!

Regards,

Gary aka "beamg5"
 

·
Registered
2016 R/T Scat Pack
Joined
·
1,595 Posts
On my auto, I have been running 87 and no issues.
I have run plenty of 87 and 89 in mine (auto) in 72k miles. No issues and no mpg differnce, but you can tell the difference in power. The 87 must cause the computer to pull back some timing...
FYI...the manual says 89 "recommended" 87 "acceptable" ... 6 speeds 91 or higher only.
 

·
Premium Member
Joined
·
688 Posts
Ethanol fee gas is the best for a couple of reasons.

1) Pure gas makes more power when burned, which will result in better mileage.
2) Ethanol gas degrades fuel lines and tanks, and it produces condensation and moisture in tank if it sits too long.

The only draw back is that you will pay more for pure gas. I always buy ethanol free gas if its available. I keep a list of ethanol free stations in my glove box when traveling. If it is not available, then I buy 93 octane ethanol blend, but only enough to get me to a pure gas station. This may be overkill, but my car sits a lot (5 months at a time) since I live overseas.

I do put fuel stabilizer in the tank before the car sits for long periods.
 

·
Registered
Joined
·
386 Posts
93 octane from the second tank. (Don't know what dealer had in it for the first tank). I live in SE Georgia with no emissions. Sounds good in theory but my car will get 2 mpg better on emission fuel (Atlanta for example)) and my 2003 Silverado will get almost 3 mpg more.
 

·
Registered
Joined
·
111 Posts

·
Registered
Joined
·
111 Posts

·
Registered
'16 A8 Scat Pack
Joined
·
11,336 Posts
Ethanol fee gas is the best for a couple of reasons.

1) Pure gas makes more power when burned, which will result in better mileage.
2) Ethanol gas degrades fuel lines and tanks, and it produces condensation and moisture in tank if it sits too long.

The only draw back is that you will pay more for pure gas. I always buy ethanol free gas if its available. I keep a list of ethanol free stations in my glove box when traveling. If it is not available, then I buy 93 octane ethanol blend, but only enough to get me to a pure gas station. This may be overkill, but my car sits a lot (5 months at a time) since I live overseas.

I do put fuel stabilizer in the tank before the car sits for long periods.
One station in my area sells 91 pure gas. Been using it a while now, and over the years I've tried every octane from every major station.

Hands down, my car idles smoother, runs smoother overall, pulls harder to redline, and gets better mileage.

IMO, worth it.
 

·
Registered
Joined
·
9,457 Posts
What is KR? Sorry, Newby question?

No worries. Newbie or not ask away anything without hesitation. Knock Retard (hereafter referred to as KR) is the response from the PCM to cylinder detonation. KR is the measure of the number of degrees of overall ignition timing advance that must be removed from the engine to prevent detonation from continuing, thus protecting the engine from damage.




Sent from AutoGuide.com Free App
 

·
Premium Member
Joined
·
3,130 Posts
93 all day 100 for the track
 

·
Registered
Joined
·
12 Posts
I have the 6M and I've been using 87. I've had the car less than a month. Is it really detrimental to run 87 if I'm not going to the track or concerned with pulling max hp all the time? This is my daily driver.

Side note. I had a hayabusa and ran 87 in it for 5 years and saw no problems at all. Even at the track.

Of you guys say 91+ is absolutely necessary then I'll switch. A refill at the pump is cheaper than my ram no matter what the octane.
 

·
Premium Member
Joined
·
688 Posts
I have the 6M and I've been using 87. I've had the car less than a month. Is it really detrimental to run 87 if I'm not going to the track or concerned with pulling max hp all the time? This is my daily driver.

Side note. I had a hayabusa and ran 87 in it for 5 years and saw no problems at all. Even at the track.

Of you guys say 91+ is absolutely necessary then I'll switch. A refill at the pump is cheaper than my ram no matter what the octane.
Use (at a minimum) what Dodge recommends. 91+ is necessary for the 6 speeds.

If I could get 98+ octane, I would be running that. As Hemizsp stated, the lower octane means that PCM will pull timing to prevent detonation. The decrease in timing required will result in the motor not performing as it could (should). Don't you want your hemi running as it should? Any less, then what's the point of having a a muscle car?
 

·
Registered
Joined
·
16,865 Posts
I have the 6M and I've been using 87. I've had the car less than a month. Is it really detrimental to run 87 if I'm not going to the track or concerned with pulling max hp all the time? This is my daily driver.
Daily driving and no hard pulls 87 is fine, the higher octane fuel only needed at higher power runs. Steady cruising down the road you don't even need 87.



Sent from AutoGuide.com Free App
 
1 - 20 of 24 Posts
Top