**Bumping this thread - On my 3.0 5MT, I run Shell 93 octane, NGK plugs were changed about 2 years ago (non iridiums), original coils, injectors, etc, and I add Lucas UCL every tank - Rotella T6 5w-40 oil just changed and used for last few years.

I'm going to have to increase my tire pressures a bit since they are a bit low, and I'll admit my driving recently is about 60/40 highway/city and on the highway we are cruising at 75 mph or so, but my last few tanks have been noticeably lower in trip mileage.

I've gotten approx 370-385 miles to the last few tanks, usually it easily gets 400+, right around 420-430. I'll increase tire pressures to 35 (I do have the heavier 20" wheels), and report back.

DISA is rebuilt
No vaccuum leaks
AFE pro dry S filter has 10k miles on it since last cleaning (intake)
New fuel filter (Mahle) waiting to be installed on my workbench
Coolant Test OBC 7 is showing 88C-90C driving, up to 95C at idle or slow speeds
Conforti Shark Injector going to be loaded up onto the DME this weekend as well

Anything else I'm missing from a mileage standpoint? Perhaps Iridium plugs, Vanos seals?

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2018 Ram 2500 6.7L Cummins 68RFE
19k miles -Bright White/Black - Big Horn Sport - Crew Cab Short Bed
2013 X5 35D (CEO's) - Born on 5/17/2013 -
82k miles - Alpine White/Cinnamon Brown/Premium Pkg, Sport Activity/Premium Pkg and Sound/20" Style 214/Running Boards