Jeep Wrangler 4xe Forum banner

what gas do you put in your jeep?

52K views 33 replies 18 participants last post by  fidelity40 
#1 ·
Hi! What octane fuel do you put in your jeep 4xe?

I put Shell's 91 V Power.
 
#9 ·
87 regular , but euro turbos like high octane..for the autobahn..no use here in usa. btw..ethanol is high octane but less efficant. and eco and savings is low.

as a chem in train i was at a petrol farm "oil raffinerie" for view days. all the petrol trucks got the same stuff filled up , the truck drivers just added the brand additives, red, blue, green, yellow...lol. thats it.
well why not belive in magic.
 
#15 ·
I don't even remember the last time I filled up, lol. So Canada says 91 now? That's the first I've seen anything other than 87 listed. For long road trips I may use 93/94 then as the cost/MPG gains are usually a wash.

As for Ethanol, we have the pressurized tank and the fuel refresh mode if water is detected. I ran ethanol in my Mustang but it was hard to find high content E85. Nothing like the smell of ethanol in the morning.
 
#19 ·
(Hopefully) taking delivery of my Rubicon in the next few weeks, so I’ve started to delve into this a bit more. Has anyone actually quantified the difference in performance or mileage between 87 and 91 octane? Driveability? Around SW Wisconsin, where I do most of my driving, the latter costs about $.70/gallon more; it’s a little hard to imagine that it’s worth it. However, since all of my turbocharged and supercharged vehicles have specified premium, I’m having a little trouble wrapping my head around the concept.
 
#22 ·
Unless you are towing or putting high stress on the vehicle, you likely won't notice any difference., except price.

2.0L ENGINE
This engine is designed to meet all emission requirements, and provide satisfactory fuel economy and performance, when using high-quality
unleaded regular gasoline having an octane rating of 87, as specified by the (R+M)/2 method. The use of 91 or higher octane premium gasoline will allow these engines to operate to optimal performance. This increase in performance is most noticeable in hot weather or other heavier load conditions, such as while towing.
 
#26 ·
If you're heavily loaded down or towing and on-the-power a lot, then 91 or higher would be better for performance and potentially reduced engine wear*. Running 87 is fine; the computer just dials back the ignition timing, reduces turbo boost and adjusts fuel flow when sensing the impending detonation under load (high compression + turbo = double whammy). There's less power on tap when timing is pulled back.

With less power on tap at a given rpm while under load, *the computer will likely then downshift a gear or two to increase rpm as compensation (causing extra wear) to further avoid detonation while increasing the coolant flow which helps keep heat buildup under control.

That said, the BTU energy content in 87 octane is higher than 91+ octane fuel. So, in "regular" driving, you'll get better fuel economy with 87 but only IF the vehicle's engine/computer is designed/programmed to handle the higher detonation potential when running 87 under "regular" driving. Driving with performance in mind or with heavy cargo or towing something will affect that...a lot. For the 4xe, I'll run 87 for running unladen but fill it with 91+ when loaded down heavy for a trip or towing something.
 
#30 ·
The only retort I have to Scotty's video is that in the US, higher octane fuels are usually obtained via using ethanol blends, which lowers the BTU content. It's been a while (ages) since I had a physics course covering thermodynamics, but it used to be that all gasoline octane grades had the same BTU content. Then the mfrs started getting cheap and using the govt push to mix ethanol.

Running all ethanol fuel provides a superb octane rating, but roughly 2/3 the energy content vs gasoline so your mpg takes a huge hit as do all the fuel lines in vehicles not equipped for ethanol. I found this out the hard way building engines with other yutes back in the day 😝.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top