Boost
June 22nd, 2010, 11:41 AM
By my estimation I should get 16-17 mpg. I am getting 13-14. My truck is a 2003 4.8 liter 2WD 4l60, stock with 105k miles. It is in good shape and running well, with new fluids and filters. It has (what I think) is lifter noise, despite synthetic oil (4 sounds per second). It has cheap Summit shorty headers wrapped, a rusty old Flowmaster, and a drop-in K&N filter, plus NGK TR55s gapped properly with MSD wires. I tuned it a few times, but with mixed results without a wideband, so it's currently back to stock. The alignment is not too bad at all and I keep the tires inflated to 40 psi (stock 17" wheels).
I am trying to figure out why the crappy 13 miles per gallon on a regular cab / short bed / 2wd??
So far I've learned that the headers make it rich at idle and I do spend some time idling in Miami traffic with the A/C on. I am practicing logging and monitoring to fine tune everything eventually, but I suspect if I tweak the idle richness out I may get some 16 MPG tanks out of it - can I adjust the idle speed VE to let it know about the airflow there? Or am I way off in my thinking?
And how can I best monitor and adjust slight variations off stoich at idle with my narrow band sensors?
Thanks, and I appreciate any other suggestions. I've already done some research on DFCO and Lean Cruise and also do not want to speed up the shifts because for a 1% improvement I'll take slow comfy shifts.
Sorry if this belongs to the "Tuning for economy" section, you can move it if you like.
I already have a bed cover and low viscosity synthetic tranny and rear fluid.
I am trying to figure out why the crappy 13 miles per gallon on a regular cab / short bed / 2wd??
So far I've learned that the headers make it rich at idle and I do spend some time idling in Miami traffic with the A/C on. I am practicing logging and monitoring to fine tune everything eventually, but I suspect if I tweak the idle richness out I may get some 16 MPG tanks out of it - can I adjust the idle speed VE to let it know about the airflow there? Or am I way off in my thinking?
And how can I best monitor and adjust slight variations off stoich at idle with my narrow band sensors?
Thanks, and I appreciate any other suggestions. I've already done some research on DFCO and Lean Cruise and also do not want to speed up the shifts because for a 1% improvement I'll take slow comfy shifts.
Sorry if this belongs to the "Tuning for economy" section, you can move it if you like.
I already have a bed cover and low viscosity synthetic tranny and rear fluid.