What gas are you running in your 392

[mikek1971]

I do not and would not run 87.
I run 90 ethanol free or 93 only. I don’t think I get any different in mpgs. Not enough that I notice. My best days are 15. Depending mostly 14.5. I really wish they made a bigger fuel tank. Don’t really want an auxiliary tank.

Thank you all for your input

 

[smiley]

I hope so️

nope, regular old gas. I have not noticed any difference other than the lower fuel bills.

 

[Riad]

We only have 91, 95 and 98 here. I run 98 which is of course the most expensive, wondering if switching to 95 will do any harm

 

[smiley]

She’s going to ping wether you hear that ping or not . It might become a problem. Just my opinion of course.

Thanks for the input. I'll keep an ear out for any changes

 

[guruman]

Thanks for the input. I'll keep an ear out for any changes

At that low an octane, and our 10.9:1 compression ratio, it's probably pre-ignition detonating on the regular, especially when putting your foot into it.


It might not be an issue, then again it might. When the knock sensor detects the detonation, it'll alter the ignition timing to help (this will cost you power). If the timing changes are able to prevent the detonation, you'll probably be fine, albeit, losing power potential.

On the other hand, if the ignition changes are not sufficient to prevent the pre-ignition, and it's pinging a "little" all the time, it can damage the engine (piston tops and spark plugs). The effect is additive, meaning the more it pings the more the damage adds up. It'll likely damage the spark plugs first, then probably blow a hole in a piston.

You might not notice any difference now, but if it keeps doing it, you'll notice eventually.

 

[Mouse]

Nothing above 91 in my area but a local store has 91 non ethanol, I run it in everything from my 1 ton dump to ATVs. Some of my vehicles may stay parked for weeks on end. The Jeeps and my F350 stay parked all winter so I just stay in the habit of running non ethanol so something doesn’t sit with a tank of corn juice watered down with climate activists tears.

 

[MDrums]

no, 87 octane.

ECU retarding timing as much as it can and engine knocking....nope not a good idea.

We only have 91, 95 and 98 here. I run 98 which is of course the most expensive, wondering if switching to 95 will do any harm

Is your gas octane listed as RON in Dubai? If so 98 RON is same as 93 here in the USA. 95 RON is 91 here in the USA. In your hot weather you should and I suggest to run the 98 (93usa) to prevent engine knock. In cooler weather you could run 91. Honestly really how much money do you save?

People can and will run 87 octane (91RON) when a vehicle calls for 91/93 Octane and CLAIM they do not hear knocking and no difference in MPG. However you can not hear all spark knock (pre-detonation). Knock is NOT GOOD for the valves and piston tops and rings. You need combustion efficiency for best power, clean fuel burn and mpg.

 

[WHLN392]

Don't really think about it. I run 93 octane whenever I'm low from whichever gas station is convenient.

Sometimes Costco, sometime Delta sometimes Shell etc.

It's a big understressed 6.4 OHV V8 in my view so a little variability is a non issue with the knock sensors etc.

I'm too busy driving this thing off and on road on any case

 

[badwrench]

My self I run regular with a 20 gallon bottle of chevron techroline ever other tank. I did not spell it right. Have watched timing with scanner on Reg and 93 and 100 octane fuel. No timing retard on reg gas or preignition. All the O2 sensor reading are in the same range. Have installed a tazer module and run it in 2wheel drive. around town I average 15 to 16.8. On hwy 17 to 17.8 as long as I keep my heavy foot out of it, and also put a pedal commander set for city.

 

[Fast-n-Furious]

92 and 93 daily. Had to use 91 in Canada for a while, also tried their 94. Not specific to any gas stations, Exxon, Costco, shell… whatever feels convenient.

 

[@JC]

93 or 91, pending availability and altitude. No specific brand. Whatever is available.

Thankfully, all the 91 around here is corn-free. 1 station has E0 93 (the only 93 in town) but it's on the other side of town so both the TRX and 392 get 91.

 

[Jeepstin392]

Thankfully, all the 91 around here is corn-free. 1 station has E0 93 (the only 93 in town) but it's on the other side of town so both the TRX and 392 get 91.

EPA regs are changing that soon.

 

[@JC]

Not in the free state of South Dakota my friend, we'll be holding out with straight dinosaur carcass fuel till the end of days...

 

[Jeepstin392]

Not in the free state of South Dakota my friend, we'll be holding out with straight dinosaur carcass fuel till the end of days...

I’d like to believe that. EPA is implementing new regs in 2025. The 8 states which can use ethanol free fuel, will be required to change their formulation.

 

[Earl 392]

Not in the free state of South Dakota my friend, we'll be holding out with straight dinosaur carcass fuel till the end of days...

Go T REX.

 

[@JC]

I’d like to believe that. EPA is implementing new regs in 2025. The 8 states which can use ethanol free fuel, will be required to change their formulation.

Pretty sure that the only change in 2025 is that those 8 states are now allowed to sell E15 all year long instead of only in the summer. Like I said, even with the boondoggle gasohol plant on the outskirts of town, it won't matter as we only have 1 station that carries E15, E30 and E85. The rest all have E10 87 and E0 91 and a couple are E10 and E0 both 87 only.

 

[smiley]

At that low an octane, and our 10.9:1 compression ratio, it's probably pre-ignition detonating on the regular, especially when putting your foot into it.


It might not be an issue, then again it might. When the knock sensor detects the detonation, it'll alter the ignition timing to help (this will cost you power). If the timing changes are able to prevent the detonation, you'll probably be fine, albeit, losing power potential.

On the other hand, if the ignition changes are not sufficient to prevent the pre-ignition, and it's pinging a "little" all the time, it can damage the engine (piston tops and spark plugs). The effect is additive, meaning the more it pings the more the damage adds up. It'll likely damage the spark plugs first, then probably blow a hole in a piston.

You might not notice any difference now, but if it keeps doing it, you'll notice eventually.

Thanks for the detail response. I'll start using the higher octane

 

[saturnfire]

Since the Owner's Manual says 91+ Octane, I would go that route. Last thing is if you have a failure they trace it to using the lower octane fuel than they recommended. I keep track of every fill up and have every receipt (scanned), so they cannot F$%$%$^ with me. One of the Guys on the TRX forum had an engine failure and they tried to say he was using low octane gas or something, but he had every fill-up documented. He did get a new Engine. Most of the folks with a 392 Spent 70,80,90,100K for them. is ~ afew hundred dollars in "savings" worth it?

 

[Earl 392]

Since the Owner's Manual says 91+ Octane, I would go that route. Last thing is if you have a failure they trace it to using the lower octane fuel than they recommended. I keep track of every fill up and have every receipt (scanned), so they cannot F$%$%$^ with me. One of the Guys on the TRX forum had an engine failure and they tried to say he was using low octane gas or something, but he had every fill-up documented. He did get a new Engine. Most of the folks with a 392 Spent 70,80,90,100K for them. is ~ afew hundred dollars in "savings" worth it?

Exactly but keeping receipts for Every fillip is going to require multiple file cabinets

 

[saturnfire]

I have one of those autmatic scanners that I used when I was self-employed to track every expense. Then all backed up to OneDrive.