kenworth t600

Roughly 3735 miles, 4.6 mpg. (to save the others from the work, and what would have been nice for you to have posted).

 

about 3900 miles /815 =4.78 mpg not real good. If your running 70-75 mph down south where its legal, your killing your self, depending on tire size/gear ratio you need to find the sweet spot (rpm) and stay there. try to keep it at 1100 -1200 rpm for optimum economy. Also there is extra maintenance you can do yourself for minimal expense Get a big pot of coffee and read this entire thread 2or3 times to make sure you get it all, if you don't understand something don't be afraid to ask it is all very important to your Cummins running properly.
http://www.thetruckersreport.com/tr...3-cummins-isx-cm871-technical-discussion.html
The education here is priceless, read it reread it and read it again, you will be amazed at the knowlage out there

 

Yeah that's bad. You ought to be able to get to 6.0 mpg heavy by just driving it right. I was interested enough to run your route miles and came up with 3791 mi, which gives you 4.65 mpg. A good place to look first would be intake plumbing and CAC leaks, as well as exhaust and turbo gaskets. Short of anything obvious, I hope you got some sort of warranty from Rush.

At 6 mpg you would have burned 183 fewer gallons of fuel, saving $713.70 @ 3.90/gal avg. One or two more round trips like that and you've already paid a big repair bill right into your tanks.

 

Well to be the 4th trucker to reply I would say its 3800 miles

As the above post noted not that good of MPG , but as noted tire size / gear ratio would be helpful if you know it, likely 3:36 ratio 22.5 rubber on a 236" wheelbase, as its likely a fleet truck it needs more than a wash and polish and a good servicing but that gets missed a lot at RUSH.

 

Since this is a 2007 model year engine, it means bad news all around. The reason is that the 2007 to 2010 model year engines were the first to use EGR, but no DEF. I considered buying the same truck and model year, but was warned by a KW dealer not to because of all the problems.

Start by having your EGRs checked as these may have to be replaced. If so, plan on replacing one every six months to a year. Check the EGR cooler and see if that is leaking. Check the turbo to see if that needs replacing. I can almost guarantee that your problem will be with the emissions control on your vehicle.

 

We have an 03 t600 and we get right around 6mpg, did u have maintanance records before buying it?

 

Have you had it properly serviced since you got it , see if theres any codes in the ECM , whats your style of driving ? how much uneeded stuff are you hauling around every extra pound costs $ to move.