Lower gas mileage than expected?
10-14-2013, 06:28 AM
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Lower gas mileage than expected? I have a 68 c10 with a stock 5.3/4l60e swapped in, 3.73 gears and a 28" tire. I am getting 13.1 and 13.6 for gas mileage and I don't understand why. I got the same in my TBSS with AWD, 4.10s, an LS2 and a 3600 converter. The truck seems to run fine, but was also slower at the drag strip than I had expected. Ran a best of 15.67 @82.75. Oh, and my converter is locking up in 4th, so that isn't the problem.
Any ideas?
Any ideas?
10-14-2013, 09:06 AM
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Compression is good on all cylinders, plugs look fine too. I'm tuning it and Afr is right about where it needs to be. I'm lost as to why it isn't making power like it should.
10-14-2013, 10:04 AM
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Do you have any idea where to look in my tune? This is only the second vehicle I have tuned so it's very possible I jacked something up. It doesn't seem to be missing and feels strong when I get into the throttle. It just doesn't seem to be as fast on the big end as it should be. When I get home I will post the tune and people can check it out if they want to give me any tips.
10-14-2013, 10:14 AM
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I posted my tune, config and a log on this post if anyone wants to check it out.
https://ls1tech.com/forums/showthrea...0#post17724120
https://ls1tech.com/forums/showthrea...0#post17724120
10-18-2013, 06:25 AM
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I found out my drivers rear brake is dragging, when I leave work I am headed downhill and have to give it quite a bit of throttle to even move. After 5 feet or so it seemed to loosen up and drive fine, but I am thinking it is still hanging up some. I pulled the wheels off and the drum was super hot, let it cool and took the drum off and loosened the adjuster. I am going to drive it to work today (only 2 miles) and see how it does. What are the chances my power and mpg problems are from a dragging brake? I don't know how much that would affect it.
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10-18-2013, 10:07 AM
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It depends on how stuck it was. Dragging a little won't change alot, but locked/fully applied would make a big difference. Ever tried to drive away with the e-brake on?
10-18-2013, 04:19 PM
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I took off from a dead stop today (no powerbraking) and smoked both tires all the way through first and let off in second. Before I adjusted the brakes it would only spin them for a few feet. That makes me wonder how much difference my brakes were having.
10-19-2013, 09:12 AM
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Yeah, honestly I don't know how I hadn't noticed. It seemed to drive fine. Now it drives great. Lol. I think it must have loosened up as I drove because it didn't mess anything up and I went on a couple 70+ mile drives with it.
10-19-2013, 08:59 PM
#13
We just had a customer that had his 2003 grand am towed to the shop. The right rear brake drum was completely locked up from sitting (he also has a house up north). He drove it until the tire wore completely through and cut the bottom part of the rim off. The whole back of the car was covered in rubber dust. LOL.