What octane fuel do you run in your 1GR-FE?

Before throwing a pump at it, hook up a scan tool and watch your fuel trims while driving. If the long term trim is under 5-6% you don't have a fuel delivery issue

 

105

 

Of course. I'll also clean the MAF, as well, assuming it's possible to clean without damaging/destroying it, and make sure the FPR is functioning.

 

I run 91 (AKI rating) with no ethanol. I never have run out of gas but my Ultragauge calibrated say i can do 560 km with a fill up at the moment with winter gas and 0 celcius in the morning. In the summer i can do over 600km. Not bad with a lift and 10 ply KO2 tyre. I drive like a grandma so this help alot !

 

I was running 93 due to spark knock issues. But as the cost of fuel was rising i wanted to go back to 87. Found the TSB describing a known issue of spark knock on 2nd gens but couldnt get a dealer to quote me a price or commit to it putting the TSB ECM change on the truck. Found a local KDMAX tuner that would do it and now I run 87 with no spark knock.

 

Look into TSB T-SB-0044-14

 

I have a 2007, that TSB is for 2012-2015.

I was planning on looking into my issue this weekend, but I got screwed into working tomorrow. Well, I screwed myself into working tomorrow. It's not knocking right now, running happy, so I'm not overly worried about it. I will be putting some new NGK iridium plugs in on Thanksgiving, or the weekend following.

 

Sorry, missed that. The one thing I thought about trying but didn't was to get a colder spark plug. Thats not really a great permanent solution but its something that could help diagnose.

 

Yeah, I'm going to start with the Iridium plugs. I don't remember where I read it, but I was mistaken into thinking the OE plugs were copper core, but apparently they were Iridium.

 

Stock plugs for the 4.0 are standard "copper" plugs, thats what I pulled out of my 2015 at about 30k. I put NGK Iridiums in because that's what I put in anything that isn't a classic car or a Ford. I've always noticed much better consistency, sometimes runs smoother, sometimes better fuel economy (last 2 likely due to age/wear on plugs replaced) and of course they last much longer. On my past couple Grand Prix GTP's it was great for reducing knock over the same temp range (1 heat range colder) compared to copper or platinum (junk) plugs. For me the extra spent is worth not worrying about them for many years and miles to come.