Dodge Challenger Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Ride of the Month Challenge!
1 - 20 of 20 Posts

·
Registered
Joined
·
1,017 Posts
Discussion Starter · #1 ·
Had no choice but to fill half my tank with 90 octane, was almost on empty. This okay to do? Anything I should do additionally to protect my engine?
 

·
Premium Member
Joined
·
4,050 Posts
Had no choice but to fill half my tank with 90 octane, was almost on empty. This okay to do? Anything I should do additionally to protect my engine?
Top it off with 93 and forget it. Will be fine.
Computers.
 

·
Premium Member
Joined
·
4,050 Posts
No 93 available around here, just 91
Dance with the girl in the room.
91 it is. Just don't run her hard till you get some of it out.
90's not that bad. Cheap 87 would be more to worry about.
You got this.
 
  • Like
Reactions: Spartan040

·
Registered
Joined
·
355 Posts
Where did you buy 90 octane? I never saw that offered anywhere before. 87-89-91-93 and 94 all offered over the years but never 90.
91 is minimum so at 90 you should be fine with less power with the car retarding the timing.

91 will be completely fine but I use 93, where do you live that you can't get 93?
 

·
Premium Member
Joined
·
4,050 Posts
Where did you buy 90 octane? I never saw that offered anywhere before. 87-89-91-93 and 94 all offered over the years but never 90.
91 is minimum so at 90 you should be fine with less power with the car retarding the timing.

91 will be completely fine but I use 93, where do you live that you can't get 93?
Thanks for pointing out the Elephant in the room. I thought it was just me but I've never heard of 90 either.
But it's a big country. And I don't get out much! LOL!
 
  • Like
Reactions: Loopy and F8HemiRT

·
Registered
Joined
·
16,216 Posts
As said, don't worry about it.

Where did you buy 90 octane?
The ethanol free around here is 90 octane.




Sent from my SM-N960U using Tapatalk
 

·
Premium Member
Joined
·
4,050 Posts
As said, don't worry about it.


The ethanol free around here is 90 octane.




Sent from my SM-N960U using Tapatalk
Where is "around here", OZ? LOL.
Just kidding. Really, about where are you?
 

·
Registered
Joined
·
16,216 Posts
South Louisiana and Mississippi, I've run it a lot in place of 91 and runs great.

Sent from my SM-N960U using Tapatalk
 

·
Premium Member
Joined
·
4,050 Posts
Florida boy. I love LA and MS. In AL for 53 years.
The South rocks!
 
  • Like
Reactions: Slidd

·
Super Moderator
Joined
·
17,238 Posts
Where did you buy 90 octane? I never saw that offered anywhere before. 87-89-91-93 and 94 all offered over the years but never 90.
91 is minimum so at 90 you should be fine with less power with the car retarding the timing.

91 will be completely fine but I use 93, where do you live that you can't get 93?
California and High Altitude areas have 91 and 90 octane respectively.

I noted in areas of New Mexico when I did a cross country drive from coast to coast of the varying grades of what is available. Another example is OR and WA top out at 92 octane for premium grades
 

·
Registered
2016 R/T Scat Pack
Joined
·
1,523 Posts
I had no choice but to fill with 89 last month when we had no gas here. It ran fine, I made sure not to get on it at all until I could refill with 93.
 

·
Premium Member
Charger 392
Joined
·
440 Posts
Ethanol free 90 octane in East Tennessee also. Good stuff but more expensive. Car was tuned with 91 octane with ethanol but last dyno was using the 90 octane, the results were identical to the 91 with ethanol.
 

·
Registered
Joined
·
355 Posts
As said, don't worry about it.


The ethanol free around here is 90 octane.




Sent from my SM-N960U using Tapatalk
I love the around here comment. I know exactly where that is LOL. I saw your later post anyway.

Thanks for pointing out the Elephant in the room. I thought it was just me but I've never heard of 90 either.
But it's a big country. And I don't get out much! LOL!
Right? I mean I never ever saw 90 octane . I have driven in CA which was in LA , Napa Valley, San Fransisco and Livermore and none of those places I saw 90 octane. I rented Challengers out there R/T's so I was looking for 89 octane when I was filling them back up.
I own a Scat Pack and had a blast renting a R/T. Such a nice balance of power and comfort. I like the R/T I think it's a great car.

Around me we have 87 , 89, 91, and 93. I don't see 94 anymore which is what Sunoco use to carry many years ago.
Maybe some of them might have it I just don't run into it.

Around me is Lower Buck County Pa which is just north of Philadelphia. I'm like 15 minutes or less from North East Philadelphia. I'm also right over the bridge from Burlington NJ.
NJ has the same exact fuel as well do here in PA. We are also at Sea Level and usually have negative D/A so excellent for racing and getting great ET's.
 

·
Registered
2014 R/T Classic 6-speed
Joined
·
277 Posts
This doesn't pertain to the 392 cars, but the 345 R/T's. I rent cars frequently for work travel; like every other week. As you can imagine, I have "status" at my chosen rental car agency. Because of that I get, with decent frequency, a Challenger or Charger R/T.

I can guarantee you that these cars are not serviced with anything but low-level unleaded fuel, and I certainly don't purchase it either before turning them in. The cars I've drive have ranged between 2,000 and 28,000 miles on the clock, and one can assume they've not seen premium fuel since the day they were rolled off the transporter and put into service. Not a single one of those cars exhibited any ill effects (knocking, rough running, etc.). Other than being a tad more sluggish than mine (I use exclusively premium fuel), I've noticed no detriment.

All this to say that the computers do a good job of compensating for the lower octane fuels. They just pull timing (and probably some other things), and the engines run just fine with no adverse effects. The cars are fat, dumb, and happy with the 87 (or whatever) octane fuel. AND, these will eventually be sold out of the fleet, and go on to private owners. At that point, the owner may decide to read and follow the owner's manual recommendations for upgraded fuel, but they may not. I don't expect they'll have a shorter service life because of the fuel choice.

Just my $0.02 worth.

Cheers!

JD
 

·
Registered
2011 gwe srt
Joined
·
848 Posts
I doubt one octane point will bother a thing. Id bet gas you buy at the pump even varys that much from truck to truck. Cars tuned for 91 if you were using 87 id say to just take it easy because your computer will pull timing and your big worry might be any lag before the computer pulls timing but if i filled with 90 id run it without worry. If your real worried dump a couple bottles of isopropyl alcohol in it. That would help prevent detonation,. I run a 93 tune in mine (diablo) and most premium up here is 91 so sometimes i get stuck i a town that doesnt have 93. Its never caused an issue. Im sure theres some fudge factor even in the diablo tune. Like dodge there not going to tune your timing and fuel curves right on the edge of safety.
 

·
Super Moderator
2016 SXT Plus Blacktop
Joined
·
26,719 Posts

A Guy
 
1 - 20 of 20 Posts
Top