Project run around.

[LT.]

There is a saying that comes to mind right now. Calculators don't lie but, liars calculate. I just finished my loop and my numbers are not adding up. I just drove an 88 mile loop. This was verified by map quest and my odometer. I just topped off the tank again just like I had it when I left. I filled it up using the same pump and I filled it up so much that I could see the fuel in the fill neck. Trying to keep everything as close to apples to apples as I could. I just put in 4.680 gallons of fuel. This means I got 18.8 miles per gallon. What the hell did I do wrong?!

On the original trip I can't remember if I was using the AC or not. I am going to guess I was due to my numbers now. This trip I did not use the AC at all. Also, in two different spots along my loop there was road construction forcing me to slow down. Once to 45 mph and the other time to 35 mph. There was no road construction on my first test loop. I know that there is no way my mileage should have improved with the addition of the new tires. So why, then, did I get a marked improvement this time out? I can only guess it was due to not using the AC, and the slowed posted speed limits in the two construction areas. There was a little wind today but, I figured it would not really matter since on the way there it was a head wind and on the way home it was a tail wind. I figured this would cancel each other out. Maybe it did or maybe it didn't. I don't know for sure.

I want to bounce another thought I had off of y'all. While we all know that the new tires are considerably heavier than the stockers I pulled off. Does that mean I should have lost as much mileage as I thought I should have? In town I can see why it would make a bigger difference than it would on the highway. In town we are always accelerating and decelerating. Lots of added rolling resistance to over come each time. But, when on the highway there really is not as much rolling resistance to over come. The added resistance was over come when accelerating to speed. Once at speed it may not take as much to keep them rolling.

Any thoughts on this?

LT.

 

[sixstringsteve]

Was it the same exact route you drove before, or just the same distance?

I doubt you changed the rolling resistance much, but you definitely increased the rotational mass. That'll play into MPG.

It's probably not much worse than having a few 100 lbs in the bed of your truck. Since it's a big truck and it was meant for hauling loads, I doubt you'll see a huge MPG difference.

Using the A/C definitely drops the MPG.

 

[LT.]

take it out and put it throught the paces and decide if you want to lift it or not. i hate the idea of lifting ifs vehicles so i'm biased. besides, the tires are going to be an amazing difference over stock and it very well could be as capable as you want. just my dos pesos

Agreed. I did not get much of a chance to check the clearance yet. There are also different options to take here. There are a few companies that offer adjustable struts. This would make it so I can adjust it between no lift and up to 1 1/2" in the front. This maybe a better option than just a 2" leveling kit up front.

Was it the same exact route you drove before, or just the same distance?

I doubt you changed the rolling resistance much, but you definitely increased the rotational mass. That'll play into MPG.

It's probably not much worse than having a few 100 lbs in the bed of your truck. Since it's a big truck and it was meant for hauling loads, I doubt you'll see a huge MPG difference.

Using the A/C definitely drops the MPG.

It was the exact route as before. But, there was a few difference between the last time out and this time. AC being one and the road construction being another. I also don't remember what the weather was like last time out. Today it was mid 80's to 90 degrees with a gentle breeze.

What can be learned from all of this? Well, for one, I can't seem to keep things as close as I would like to. I was striving to keep things as close to apples to apples as I could. It is apparent I failed at that. I don't know what else I could do to fix it so, I will just have to learn from my mistakes here and continue on.

LT.

 

[N-Smooth]

you tried. it's not like a couple mpg's matters one way or the other. i'm sure you wanted to find out just for scientific purposes anyways. besides, the truck looks good and that's what really matters

 

[sixstringsteve]

It was the exact route as before. But, there was a few difference between the last time out and this time. AC being one and the road construction being another. I also don't remember what the weather was like last time out. Today it was mid 80's to 90 degrees with a gentle breeze.

What can be learned from all of this? Well, for one, I can't seem to keep things as close as I would like to. I was striving to keep things as close to apples to apples as I could. It is apparent I failed at that. I don't know what else I could do to fix it so, I will just have to learn from my mistakes here and continue on.

Sounds to me like you succeeded! You throw bigger, heavier tires on, and get better MPG. Teach me how to do that!

 

[Cascadia]

I must have missed it even though I feel like I've kept up with the thread. What was your original mpg before the tires?

 

[LT.]

you tried. it's not like a couple mpg's matters one way or the other. i'm sure you wanted to find out just for scientific purposes anyways. besides, the truck looks good and that's what really matters

I did try but, I should have done a better job. Thanks again for the complements.

Sounds to me like you succeeded! You throw bigger, heavier tires on, and get better MPG. Teach me how to do that!

I am not sure I know what I did. Lol. I know that the numbers don't reflect the obvious here. I know that there had to be some loss but, perhaps it is not quite as bad as I had thought.

I must have missed it even though I feel like I've kept up with the thread. What was your original mpg before the tires?

The first loop net me 18.1 mpg and today I got 18.8 on the exact same loop. There was a few differences between the two loops but, I think the biggest was not using the AC this time out and the construction zones had slower posted speed limits. Another thing that got me thinking was when I did the first loop to get a base line I was using the spare tire and wheel on the drivers rear. The spare is a steel wheel and the other tire (with the impact break in the tread) was in the bed of the truck. This time I had all the original aluminum wheels on the truck with the spare mounted back under the truck. Also, I know that the tires this time out were properly inflated. On the original trip I don't know for sure. The light on the dash was on but, I figured it was due to the spare tire being on the truck and not due to a tire that had low pressure. To many variables to keep track of here.

LT.

 

[sixstringsteve]

Cool. 18.8 mpg is great mpg for a vehicle that big. I'll bet the leveling kit doesn't lower it much more than .8 MPG.

 

[jeep-N-montero]

Sounds to me like you succeeded! You throw bigger, heavier tires on, and get better MPG. Teach me how to do that!

This works to an extent, the principle being that the engine runs at a lower rpm to maintain the same speed than previous. One or two tires sizes larger than stock on a v8 or diesel has minimal impact on the amount of torque required to turn them, especially if it is taller but narrower or same width as stock. But once you put a wider and more aggressive tire on there it starts to create more wind resistance and friction across the tread of the tires. Additionally, the taller the vehicle the more effort it takes for the engine to move it.

 

[N-Smooth]

yeah, when you have that much power it's not nearly as big of a deal.

i also don't think using the a/c makes a significant difference. on old, less efficient vehicles... sure. newer vehicles, not so much.

 

[LT.]

I am not too sure what to expect with this truck through the build. Thus far I have been slightly miffed by the addition of the larger tires. As of now I am looking at a set of adjustable struts for the front and maybe a 1 to 2" block for the back. The block will be the same amount of lift as the front ends up being. I want to maintain the factory rake no matter what I end up doing with the suspension. I am seriously looking into a Magnaflow cat back exhaust for the truck. But, it is going to have to wait until I get Christine finished. That's a problem when you have too many projects going on at one time.

Thanks again for all the ideas and support. It is greatly appreciated.

LT.

 

[LT.]

Time for a small update. Thus far I still have not been able to get the tires to rub on the truck. So, I suspect that it will not get the 2" suspension lift I was originally thinking it would get. This is good news in the fuel mileage department. But, I can say that I have taken an honest 1 mpg loss while driving in town. I think we all suspected that as well so, it really was not a big surprise. I am still wanting to try and gain that 1 mpg loss back with the cold air intake and exhaust modifications. I don't think I will get it all back but, I do think I can get most of it back.

Thus far the tires have impressed me every step of the way. The tire noise is more noticeable the more I drive it. Again, it is not bad and I have a set of all terrains on my Escape that make more noise than the Toyo Open Country MT's do. I have been on them now for about 500 miles. Thus far I have had them on the highway, in town, gravel roads, and now in the rain as well. In every situation they have continued to preform better than I had expected. I hope to have them in some mud later this summer and maybe even some snow later this year. When I do rest assured I will post up the performance when it happens.

LT.

 

[LT.]

It has been a bit since I have updated this project. But, I did do another addition today. Today Betty got a new bed cover. This one was made by ARE and is a solid fiberglass cover that is painted to match the truck. I got it for free today and had to install it. Here are the pictures.



You can see on the rear where I had to remove the tail gate spoiler so the cover would latch correctly. I measured for a stainless trim piece and I think it will cover up the holes in the tail gate. I hope that sometime this week I can drive my test loop again and report any changes in fuel mileage. I am hoping that this little modification will improve the mileage some.

LT.

 

[sixstringsteve]

great looking truck.

 

[ChestonScout]

wow!



How have I missed this thread???


Truck looks awesome on the new tires Rob!

 

[LT.]

great looking truck.

wow!


How have I missed this thread???


Truck looks awesome on the new tires Rob!

Thanks fellas! The truck is doing exactly what it needs to so far. The real test will come when I get out to do some hunting in Iowa and Nebraska. I was hoping to get to go Elk hunting in Idaho this fall but, things did not line up. Maybe I will get to go deer hunting later this year. Maybe I can convince the wife to let me out of the house this evening to do my test loop and check the mileage numbers.

LT.

 

[N-Smooth]

I love it

 

[LT.]

Well, the results were not what I expected. Checking the weather would have been a great idea before I left but, being stupid I did not look first. I ended up with 18.1 mpg again on this test loop. I had windy conditions this time out and according to the weather station the winds were gusting up to 45 mph. However, while going down the front hill the mountain blocks the wind pretty well and the truck was going faster down the hill than usual. This tells me that the bed cover is reducing drag to some degree. I know that my data does not support my feelings but, I think the truck should be getting better mileage now than it did without it. Again, according to Mythbusters the bed cover should not make any difference. So, I am just going off of feeling. The rest of the trip was uneventful but, the mileage just does not support my feeling. Weird but, I cannot argue with the data.

LT.

 

[sixstringsteve]

how heavy is the bed cover? Even though it may have less drag, it does add weight.

 

[LT.]

how heavy is the bed cover? Even though it may have less drag, it does add weight.

I am not sure. I picked it up and mounted it by myself so I would think it was only about 80-100 lbs or so. It really was not heavy at all, more awkward than anything.

LT.