Back story: I always wanted a Disco, and finally decided I needed an extra truck to not kill the other vehicles with all the activities I like to do. I shopped around for about 6 months, but there was always something I was afraid of with each one I found, or too much work needed. The one thing I did notice though, is that all of them I looked at ticked in one way or another. I finally found one which had everything I wanted, plus all of the major things done in the last year (Head and all gaskets, timing chain, radiator, etc). She ticked though... maybe even a touch louder than others I drove. But, she also had 117K on the clock while others I looked at had less. I figured what the heck, let's give it a shot though.
As others have said here, I surely did not want to spend my time worrying about it, but still wanted to see what could be done. So, I installed a good new sound system and kept it out of my head!
I used the truck all winter for ski trips as well as general driving as the roads were pothole ridden and crappy from a rough winter. I've put about 4K on her, and in that time my MPG has risen and the tick is much quieter now and constantly gets better. Here are some of my observations:
When acquired: 13 MPG, changed oil to M1 5W-40
500 Miles: 1 Bottle of seafoam in engine, 1 in intake, 1 in fuel.
600 Miles: Changed oil, M1 10W-40
600 Miles+: Use recommended dose of Lucas in each tank (constantly)
1200 Miles: 1 Bottle of seafoam in engine, 1 in intake
1300 Miles: Changed oil, M1 10W-40
Tick getting a bit better; MPG constantly around 14
2000 Miles: 1 Bottle of Marvel Mystery Oil in oil, recommended amount in tank.
2500 Miles: Changed oil, M1 10W-40
Tick getting a bit better, MPG constantly around 14.5 MPG
3500 Miles: Bottle of Marvel Mystery Oil in engine
3700 Miles: Changed oil, M1 10W-40
Tick getting a bit better, breaking 15MPG.
The last two tanks I got 15.5 and 16. The later was more highway driving, but also included driving in NYC traffic.
The truck still has a tick, and sounds more diesel-like when sitting and idling (not because of the tick though). But, to me, I have seen a marked improvement in both sound and economy, so it seems like things have moved in the right direction. As far as driving habits, I am surely not easy on the throttle, and am much more likely to pass than be passed. I also have a ton of hills by me, and a fair amount of stop and go + around town driving.
Just wanted to share findings though, also poll the audience about what kind of MPG they are getting. Honestly, I don't care about the MPG as I didn't buy the truck for efficiency, but I do think there is usually a direct correlation between MPG and how the vehicle is running.

 

My average is 13.4MPG and my best tank average was 14.6MPG.
Coincidentally I dumped a qt of MMO in my engine with Rotella 15W40 and ran 500 miles with it, that was at the same time I got my best MPG. The tick died away completely for a week and then came back after I changed oil. I don't believe in snake oil but I thought WTH and used the MMO to see if it does anything. Maybe there is some marvel in the mystery oil after all.

 

Just looking at the oil color when done, I think it did a good job in there. Same with the seafoam. I also think the Lucas in each tank nets me maybe 1 MPG better as well. I have proved in the other cars I have there is a small increase, and a slight decrease in operating temps (even at the track).

 

I buy Lucas in bulk.

 

I have met many old timers in my life that have sworn by Marvel Mystery Oil, especially the ones with classic cars. I have always thought about using it but never have. Now that I have read this thread I am going to finally try it and see what happens.

 

Prior to roof rack, lift and tires, 90% highway driving,with Lucas UCL in every tank = ~18 MPG.

After roof rack, lift and big tires, 95% city driving, no Lucas = ~13-14 MPG.

I've used the same 2 Shell gas stations over the course of my changes and always run 92 octane. I also have a Volo FS1 (fuel saver chip) that got me between a 1-2 mpg increase, I like to think it cancels out my roof rack

And to answer your poll question, YES I believe there is a direct correlation between MPG's and how the vehicles is running.

 

Imagine that.....you maintain it and it runs better and uses less fuel. I think you're on to something here.

 

In college I had an old 91 Jetta Diesel as a beater, and started using it in there. 200K on the car. I would use it (like I did here) as a cleaner really. It made a HUGE difference in that car. I have not used it since, as everything else I have has been new and cared for by me (Synthetic oil, good gas, etc). I figured with the truck I would give it a shot to try and clean it a bit. You could see evidence of the prior HG failure, so I am sure each cleaning takes a bit more junk out.

 

I used MMO for about 800 miles right before I dropped the oil pan and changed the oil pan gasket gasket. My though any extra gunk would settle in the oil pan and I could clean it out.

I too have the Volo Gas Saver installed.

I exclusively use Shell V Power 91 Premium, for 4 years now. Also BG44k every 10,000 miles or every other oil change as I can afford it and find it for a deal on eBay.

My gas milage is tracked perfectly with the Gas Book iPhone app. I avg 14.68 mpg. I drive mostly short city trips and hwy driving one day per week.

What Lucus additive are you all using. Upper Cylinder lubricant? I have heard that is good, but is hard to find in my area. I only find the standard fuel injector cleaner. I figure the shell V power has enough good additives in it, it might be over kill.

Here are the Stats for kicks on my Gas Saver App. Year to date:
Fuel Economy 14.68MPG
Total Cost $624.97
Total Gallons 178.73
Total Miles 2624.00
Average Cost per mile $0.24
Average Cost per Gallon $3.50
Average Cost per Day $7.02

 

I am thinking of giving MMO a try.
You add that as a substitute for the same amount of oil right? (Eg. if the truck calls for 6 Qts oil, you add 5 Qts oil and 1 Qt of MMO?)