Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Retired, broke and have gas guzzler Nissan truck

JRMichler · 09-07-2011, 01:20 PM

Yeah, I would also expect a small truck to get similar mileage to the Mercedes. Here's a few things that will kill mileage 30 or 40%:

1) Ignition timing retarded about 10 degrees. I don't know how this could happen with a computer controlled engine.

2) Fuel mixture always on full power enrichment. I don't know how this could happen with a computer controlled engine - maybe a WOT throttle switch failure?

3) A really bad burned exhaust valve. A compression test will diagnose this.

4) A seriously dragging brake. You would feel the heat radiating just standing near it.

5) (Maybe) Camshaft out of time - worn chain (does your truck have a timing chain or a timing belt?) or belt/chain jumped a tooth or two.

6) (Maybe) Worn lobe or two on the camshaft. This happened to me years ago. I know it will reduce power, I don't know if it kills gas mileage.

7) Something I haven't thought of.

09-07-2011, 01:20 PM	#23 (permalink)
JRMichler Master EcoModder Join Date: Feb 2011 Location: Phillips, WI Posts: 1,013 Nameless - '06 GMC Canyon 90 day: 37.45 mpg (US) 22 Maverick - '22 Ford Maverick XL 90 day: 42.77 mpg (US) Thanks: 188 Thanked 466 Times in 287 Posts	Yeah, I would also expect a small truck to get similar mileage to the Mercedes. Here's a few things that will kill mileage 30 or 40%: 1) Ignition timing retarded about 10 degrees. I don't know how this could happen with a computer controlled engine. 2) Fuel mixture always on full power enrichment. I don't know how this could happen with a computer controlled engine - maybe a WOT throttle switch failure? 3) A really bad burned exhaust valve. A compression test will diagnose this. 4) A seriously dragging brake. You would feel the heat radiating just standing near it. 5) (Maybe) Camshaft out of time - worn chain (does your truck have a timing chain or a timing belt?) or belt/chain jumped a tooth or two. 6) (Maybe) Worn lobe or two on the camshaft. This happened to me years ago. I know it will reduce power, I don't know if it kills gas mileage. 7) Something I haven't thought of.