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Discussion Starter #1
Just bought the truck a couple of days ago. At first it got 14mpg avg with mostly freeway driving. Read up on additives and decided just to try the Lucas first. Drove 270 miles yesterday with 50 of that in town miles. Averaged 18.7mpg. My freeway speed is 80mph which for me is 2500rpm. It cost me $10 for a 32oz bottle. So I can get three fillups out of one bottle. I really need to get the best mileage I can since very soon I will be commuting 240 per day with the truck 4 days per week. Now I need to find a cheaper place to buy Lucas at. Anyone know?
 

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That hand calculated mpg? If so, that's pretty good, I would like to know how more tanks of it do. If that is by the DIC, I wouldn't trust it yet until you fill up and calculate it out. It might help that you have a 2wd too. 2500 rpms at 80? Seems high for a 6 speed, but I don't know the ratios, but with stock tires, that would be pretty close I guess. I think I am 2000 at about 68-70mph....I have the allison and 285s though. Not too many times I get to get up to 80 unless I am passing someone on our great highways here :) Unfortunately, our trucks seem to get the best mileage at about 2000 rpms.
 

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Discussion Starter #4
I plan on it. Who knows how the previous owner treated it.
 

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It's the fuel treatment. I have 3.73 gears and 265/70r17 tires on chrome factory 17" wheels. One thing the wife brought up with me is that the truck came with 245/75r16 tires and now with the 265/70r17 how much speedo error do I have. I have a portable GPS that I will take out and figure out how accurate it is tommorow. The discount tire website says the 17's are 1.14" larger diameter than the stock 16's. So that means I am actually indicating slower than actual unless it's been reprogrammed for that tire size.

The overall goal for my truck is to be able to set the cruise at 85mph and get at least 20mpg on the highway. Here in Arizona our highway speedlimit is 75mph and most everybody goes 85-90, even some semi's that have enough a$$ to do it.

The big debate for me also is whether to lower the truck a little or lift it a little. Whether the aerodynamic benefits of a lower truck will be better than the decreased RPM of lifting a little and running a 33 to 34 inch tire.
 

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wow my 285/75's really throw off the speedo
 

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I finally used my GPS to get the speedo set using the Quadzilla and on my last trip of about 280 miles I averaged 18 mpg going 75-85 the whole time. Not bad in my book. I just wish diesel wasn't as expensive as premium. There is something wrong when my 500bhp GTO is cheaper to drive.
 

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I guess I have a newbie question, how often should you put additives in? Mine is an '07 Classic with the LBZ, do I need to be hitting each tank/every other?
 

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I wish I was getting 18 mpg. My truck has been getting 14.5-15 mpg ever since I purchased it at 138K. Maybe the compression is down, injectors may not be spraying as good as they can, or something else. Nothing has improved it even driving slower.

I also have had zero luck with additives. I seam to always hand calculate lower fuel economy when I put additive in the tank. I say this based on my experience with a 1994 6.5TD C3500, 1999 Ford Power Stroke F250 and now my 2004 D/A Dually Crew K3500. Normally about 0.5 to 1.5 mpg worse with the additive. You bet, I don't use any additives any more, why spend the money.

I also don't believe the DIC since every single vehicle I have ever owned has told me I get better mileage than I actually get. Current 2004 is 1.5 to 2 mpg better than what I hand calculate. Check your trucks again and base it over several fill ups. This is the only way to really know for sure. My drive is about 60% highway at 70-75 and 40% City. Parts of my drive, I push it to 80 and know that hurts the economy. Average MPH is typically between 38-41 over the entire tank.

Steve
 

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I gotta chime in on this one....

Besides the fact that I'm an Owner Operator and can co-sign the benifits of LUCAS products, my wife works for "Chevron Research and Technology" (for 32 years) in the oil additive approvals dept.

If you go into any Truckstop in the nation, you will see that they all sell Lucas products. When I first started driving longhaul, I bought some Lucas oil additive and brought it home so my wife could take it to work and find out what it's really all about.... All I can say is ~ After my wife was done with the testing, she called me while I was on the road and told me to continue using LUCAS!

My fuel mileage before using the Lucas was 5 to 5.5 mpg... as apposed to 6.23 mpg using Lucas. These calculations were made using gps, on flat ground while running 80,000 lbs. and crusing at 74 mph.

Bottom line... Lucas works!
 
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