Gas in the Jeep

Quick question guys. Is there any harm putting super unleaded gas in the jeep? I know the owners manual says not too but was just curious if anyone has actually ran their jeep with it. What are the potential problems? I haven't done it, but I'm having a debate with a friend about it.

Thanks and Happy New Year. I haven't been on for awhile.

Derrell

Hi Derrell, HAPPY NEW YEAR TO YOU .....
No harm what so ever, just a huge waste of money.
Your jeep does not need high octane fuel, it should run on 87 octane without a problem at all.
Those things will almost run on peeee.

On the other hand,I put high compression pistons in my harley engine and I have to run 93/94 octane fuel in it all of the time.
Other wise it pings/detonation, if I didn't it would ruin pistons/engine in no time .

Is it pinging ( IT SHOULDN'T )or is something not right with the way it runs?
Are we going for bragging rights here as in ( look at me I use premium fuel in my jeep) if that is the case, forget about it and use regular gas in it !......

No problems. I'm using 87, but I just purchased a programmer and one of the options is for "power" but I was told if I use that option I need to use 91 octane. I mainly bought it so when I put bigger tires and a lift on it I can program it accordingly. So thats what the debate was over.

THE PROGRAMMER IS PROBABLY GOING TO CHANGE THE IGNITION TIMING ADVANCE CURVE OR MAP SENSOR READINGS. AND AS A CONSEQUENCE OF THAT IS HAVING TO USE HIGHER OCTANE FUEL.
SOME PROGRAMMERS USE A RESISTOR TO FOOL THE ENGINE COMPUTER TO MAKE IT THINK THAT IT IS STILL COLD ( COMPUTER THINKS ENGINE IS NOT UP TO OPERATING TEMP) GIVING IT MORE FUEL, LIKE A CHOKE STAYING HALF CLOSED ON A CARBURETOR.
IF YOU USE A PROGRAMMER FOR POWER REASONS (YOU ARE NOT DRAG RACING IT) THEN YOUR RIGHT FOOT IS GOING TO BE ON PEDAL MORE AND YOU WILL USE MORE FUEL AS YOU KEEP SAYING, IS THIS WORKING.

IF YOU HAVE A 4.0, THEN IT SHOULD ALREADY HAVE ALL THE POWER IT NEEDS FOR TRAILS AND ROCK CRAWLING, AFTER ALL HOW FAST CAN YOU GO WHILE DOING THAT...
IT IS NOT A PORSCHE AND WILL NEVER EVEN BE CLOSE TO ONE UNLESS YOU PARK NEXT TO ONE,, HAHA.
PUTTING ON A INTAKE AND A MAGNAFLOW STAINLESS EXHAUST SYSTEM WOULD BE A GREAT PERFORMANCE MOD TO DO WHILE STILL USING 87 OCTANE FUEL.
Caps lock button was stuck on, SORRY..

I thought you were yelling at me..haha.

Yeah, I have no interest in the power setting. Really just want it for the tires and lift and if I get real crazy the gears if I change those out. This is still all new to me as I am taking the upgrades nice and slow. I did get a new exhaust and intake and have noticed a little more power. I do like the sound of it too. Bonus is in March so I'm hoping to have the new tires/wheels and lift for the spring.

Sorry no yelling here.
I have had my tj for 4/5 years now and I have experimented with a bunch engine of mods.
I installed a header, complete magnaflow s/s exhaust from manifold to tail pipe ( mandrel bent and larger inside diameter pipe and high flow cat) and a aem intake system.

I lightly ported / polished the cylinder head, installed performance high flow rate / better atomizing fuel injectors, newer style intake manifold, throttle body spacer, lower temp thermostat and modified the housing, accel coil , ford 150 8 mm spark plug wires, and others that I bet I did not mention, im sure..

After all of that experimentig, I removed header, throttle body spacer, low temp thermostat and performance injectors,
It runs great and I get to run it on 87 octane gas
I have done all of the work myself so I know what I did and how it worked out or didn't.

For what it's worth, I ran my TJ with High Octane for 3+ years without issue. I thought it would be better since I commute in mine, but was really kind of counter productive for me. I replaced my 210 thermostat with a 190 one years back, thinking it would help with keeping the engine cooler. It does, but the high octane requires higher temps to ignite, so I was really just negating the octane rating with my lower thermostat. Speaking of which, I really do need to return the thermo to stock speck so my heater will get hot again.

Why does the owner manual say not to use higher octane? Or not recommend using it.

My guess would be because the temp of the engine wouldn't get hot enough to reach the flash point of the high octane. Basically, it just wound't use it efficiently. Doesn't do harm, though.

say you and I each drive 250 miles with same vehicles, at the end of the 250 miles it cost you more to get there that's all,,,
Was there a need to use higher octane fuel? no, you were not racing!...
At least I wasn't. LOL
There are speed limits etc .

Aren't speed limits inherent in a Jeep?

There are alot of things that jeeps are great for.
But modified jeeps are not famous for great gas mileage or the ability to maintain highway speeds without a bit of throttle getting involved.
Around here there are just so many hills and you are constantly on and off the throttle, even on the highway. = crappy gas mileage.

The wranglers are about as aerodynamic as a BRICK on wheels!!!