Fuel mileage one a Cat with 4.30 rears

3406 in a 07 is a glider or motor swap. doesnt matter what year it is. 3406 would never have an egr buddy

 

your fuel mileage is about right. i run about 5.5. sometimes 6

 

And..... a "C-15" from 2007 is a "C-15 Acert" which has Cat's early EGR for emissions. Not saying its bad or anything.... thats another discussion....just clarifying for folks.

 

If OP could spend any amount on a truck and his only concern was hauling 90k gross with the best fuel economy , what would that truck look like and what is the best fuel economy he could hope for?

 

You’re not getting mpg with weight I don’t care what kind of truck it is,

my uncle has a few trucks pulling buckets a 96 kw with a 5ek and 15 over 1124.5, that runs 100k every day and does about 5.5-5.75, runs about 1750 at 65 and wide open I think is 74 at 2100

spare truck is a t800 with a c12, rtlo 13, 4.33 and 12.22.5 pretty consistent at 5.5 with that one, small block has to work a little harder, 68 mph at 2100 rpm

My w9 pulls a fridge, and has more wheel base (drag) and I can get upper 5s rather easily at ~75k with 3.55 and an 18/n14, I’m sure if I actually tried I could get into the 6s, but I don’t do enough miles to really worry about it, but I’m down around 1450 at 68mph.

However an acert isn’t exactly the most fuel efficient engine as is,

 

Delete, delete, delete.

 

I've been racking my brain trying to remember for sure but I'm pretty sure cat didn't use EGR until the SDP prefix engine. And cat didn't call it EGR either, it was the same thing but slightly different. I'd love someone to tell me different but the bxs, mxs, nxs used higher compression combined with the IVAs and compound turbos to meet emissions. Adeptape just did a video about it recently. But I could be mistaken, I feel like I'm missing half my brain today

 

They called it CGI (another acronym!) which stands for Clean Gas Induction. Instead of pulling exhaust gases off of the exhaust manifold or by the turbo, they pull it after the DPF.

 

Yep. No EGR until the SDP prefix. CAT swore up and down they would never resort to EGR, so they called it NRS (NOx Reduction System). Because J1939 is a standardized system, everything in CAT ET refers to it as EGR but in SIS they call it NRS. Kinda confusing if you're new to it lol.

 

Ok wait.... I thought I finally had this figured out! So basically your saying some of the Acert's (all compound turbos) didn't have Cats EGR? So before the SDP prefix? Any idea on year range for these Acerts. Thanks!!!

Edit: changed to compound turbos