Soot build up?

That's what I was gonna say, looks like it's burning rich..

 

Hell, my diesel Hilux doesn't produce that much soot.

 

Probably not soot, more like exhaust condensate in the morning and road debris / dust collecting on the moist area.

Very plausible.

 

Interesting. Got a bit of soot here too. 2500 miles. Hmmmmmm...

 

2016 with 11,XXX on it. I let it idle in the summer to cool it down but still don't see anything like that.

 

That's normal

 

I live in Louisiana and have a morning commute, full of fog. Humid AF. And I've never seen this. 13k on mine.

 

I smell a recall.

 

Humidity could mean your road debris is also damp, if a dry climate with low humidity, dust and dirt can accumulate to moist areas near the exhaust as the truck is driven while coming up to temp on cooler mornings. Part of why you see exhaust when a car is first started until the moisture evaporates and you no longer can see the moisture cloud. Same thing when you see water drip from the tailpipe. Possibly not evident in Louisiana humidity in the summer.

 

That's about what I had, I didn't have it on my T4R, so I did take notice.
But I never had bad mpg, I was getting 24+mpg on stock tires & suspension.
OP should be getting at least 18-19mpg imo on the freeway at least even with his tires, so I would get it checked out.

And even though there's no recall for some cps, it doesn't mean everything's beautiful, there's a thread here:

https://www.tacomaworld.com/threads/steering-floor-vibes-clean-your-maf.495306/page-10#post-15465898

I highly recommend reading his findings to anyone having issues.


Hope that helps!
Cheers!