Boostman76

For the Canadians on here with jb4s...have you ever logged using different fuels? So many opinions online regarding which fuel is best...petro 94 with ethanol, shell 91 no ethanol and even some honourable mentions for husky 94 (apparently knocks less than petro 94)? Waiting for the weather to turn here before installing my jb4 but figured I'd ask to see what others use and/or prefer.

Hungalow

Imo I think the shell gives ya more pops and bangs and just runs better. When I use petro can. 94 octane in the summer it seems like the car runs a bit hotter.
I am also curious to see the numbers.
You in the GTA???

Boostman76

yes vaughan here...you? Do you also have a jb4 or stock?

mau108

Check this post on BITOG

https://bobistheoilguy.com/forums/th....301435/page-2

jonathan358

I share similar experiences. Esso 93/Petro 94 might give a slight increase in power but exhaust goes silent. Shell runs best. Need that 94 V-power like they have in the states.

Boostman76

thanks...are you stock or tuned?

jonathan358

Stock. With a tune, you should definitely use 94 or at least 93 octane unless you specifically ask for a 91 tune.

Hungalow

I am in Oakville, close to escarpment twisties 😎. Am stock but gonna do the jb4 ...H&R this spring. Just bought it out so shes due.

Boostman76

nice...will have to get out and take them through their paces! If you can, suggestion would be to go for h&r vtfs...the sedans have a tendency to have a reverse rake with when on springs only

user33

Interesting. I've run Chevron 94 (no ethanol) on the track in both the C43 and C63 S. Exhaust note is glorious in both cases ... but no different from any other fuel I've run (normally 91/92 with 10% ethanol). If I use 94 (or anything like it), I want it to be from a station that sells _lots_ of it (e.g., one that's close to a track). Some stations that have an ultra-high octane option don't sell much of it so the fuel can become quite aged.

I'd also like to see some actually engine data comparing different fuels under similar scenarios.

19’43s

Use 94, higher octane always better don’t play yourself

jonathan358

Check out the link in the post above, it has a lot of good information on ignition timing for different fuel grades. And I think you are spot on with the last statement about going to a high-volume station for 94.

I just filled up with 94 (10% eth.) a few days ago and the power difference was quite noticeable compared to my usual 91 (no ethanol) fill-ups. Maybe the first couple times wasn't as fresh so the 94 didn't feel as big of a difference. But after the last few days, I gotta say 94 makes a huge difference in my C43 in terms of how the power builds and the increase in peak engine torque.

In the thread it talks about retarding timing with lower octane which makes sense as to why 91 makes my car backfire a ton more and is louder on the AMG upshifts.

I honestly might convert to 93+ from now on for the power increase. The only thing I dislike is the thought of ethanol eating my fuel lines, clogging injectors with loosened debris, and absorbing moisture and leaving water layers in the tank..