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    Troutdale, OR

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  1. I have gone down in tire size from 35 inch tires to now a 265/70R17 on third gen steelie rims. Even though my final ratio is closer now it seems like I still can't break over 19mpg tank average. My average overall with 35 inch tires was around 18-18.5 and now it seems like my average has gone up just a little to 18.7-18.9. I've been playing around with the timing still on the quad but no matter what timing I'm at it seems like it really doesn't make a difference. I'm at 1870 rpms @ 65mph and that's the speed I drive at most of the time. The only thing I can think of is my rotating mass. The 35's were on 17 inch alluminum rims and these other tires are on the steel ones. I think overall I've only shaved off about 20-30 lbs of rotating mass. Only other thing I can think of is going with the 3rd gen alluminum rims if I can get a good price on them but I still feel like I should be somewhere in the mid 19mpg range with my final ratio. What could I potentially gain with going to a 245/70R17 tire? Any thoughts?
  2. I just talked with the girlfriend and I am able to leave my current wheels and tires at her house. I got a pair of 3rd gen 17" wheels with 265/70R17 Hankook tires. One thing I didn't realize though is that they are the steel ones and not the alluminum I got them for $90 though so I thought that was a pretty good deal. 40% tread left too. Hopefully I can get better mpgs with these since my final ration will be a little closer to what it's supposed to be. It looks like the weight overall though is going to be only a couple pounds lighter per wheel/tire than what I have on it right now. I just hope that my fuel economy goes up a bit.
  3. Do you have any pictures of those tires on your truck? I just don't want the 285/65R17 or 285/70R17 to look funny on my truck since the rims are a slight negative offset. I'm just thinking if I should sway towards the 65 since tire blow outs don't really happen that often and I still have my spare that I might be able to use for an emergency. Even though the spare is small, I still should be able to use it in a dire emergency without damage to the diff right? 3.54. yea I think the 285/70R17 would look decent, I just don't know how a 285/65R17 would look like on a slightly negative offset rim. I just don't want it looking bad either lol.
  4. Well I thought I could get 285/65R17 but the tire shop had a good point and said that if I had a blow out or something happened with the tire that it would be difficult to get that tire anywhere since it is uncommon. Should I still get that tire or just make a compromise and go with a 285/70R17? I'm looking to get a small boost in fuel economy.
  5. I've looked into regearing before but it just seems pricey to do on both diffs right now. I'd have to get the Dana 80 ring and pinion since mines the 80/70 hybrid. It's looking like I'm gonna have to go with a 285/65r17 tire. That's the smallest one that will fit my rim (17x10). I have three options to choose from; Mickey Thompson Deegan 38, Cooper Discoverer AT3, or Yokohama Geolander G015. These are all all-terrain tires but the Yokohama ones have the least amount of tread according to the specs. Kind of leaning towards the Mickey Thompson's but not sure. Any opinions?
  6. That's what I'm gonna get here soon once my tires are worn out. Well if it can fit on the rim. If not, I gotta go with 33's. It would be pretty nice to get 19.5 at those higher speeds. Does it go up for you if you drive a bit slower?
  7. That's pretty dang good fuel economy! You can't even get anywhere near that in a new truck. One of the reasons why I'm gonna stick with my 2nd gen. Apparently those 245s came stock on my truck according to the door sticker. Why didn't the last owner just keep those on? Would have saved me the trouble
  8. Once my 35s wear out, I'll be going to either a 32 or 33. Might even change the gearing if I have to. There have been some articles that I've read where people say they have gotten around the 20-22mpg mark with 35 inch tires and same gearing but I just don't see how it's possible especially going faster. If I kept my rpms around 1800-2000 going a bit faster, would I just be using more fuel with those 35s and having a drop in mpgs? That's what I've always thought. I just don't really drive 75-80 that often.
  9. I've wondered the same thing since I have 35's. After I installed the 7x.010 injectors, my load has gone down about 5-8% and I noticed a slight drop in egts but that could have been from a tail wind. I think the percentage drop may be from the pop pressure being set at 320 bar though. My best mileage so far has been 18.9 tank average with 18.5° timing @ 1650 rpm going 65 mph. I'm starting to experiment now with the lower timing values but my egts have gone up a little which is making me think that this tank average will be a bit lower but I guess I'll see. Here's a really good article I found. It doesn't pertain to the Cummins engine but it does have a lot of good information on timing, cetane, etc that I believe we can put to use. http://www.maxxtorque.com/2009/03/diesel-timing.html?m=1
  10. Do you know if it drops down to 42 in summer? I probably shouldn't be using a cetane booster with the B20 over here. I'm starting to think that it makes my fuel economy worse.
  11. I'm at 700-750 now with the lower timing instead of around 650 with timing advanced around 18-19. Do you know what your winter cetane number is over there in Idaho?
  12. If I get the timing right, should I see a low engine load, low oil temp, and low egts? I'm trying the winter economy tune with a 2° cruise timing advance instead of 1° but it seems like my egts have gone up as opposed to higher timing with lower egts. Can good mpgs be had with a slight increase in egts regarding the lower timing?
  13. I have a viton o-ring assortment that hopefully will work. The adapter said it came with a crush washer though. Should I just use that o-ring then instead?
  14. I just got an adapter ordered. Will a crush washer work instead of an o-ring or will I definitely need that o-ring?
  15. Do you know what size it is? If it's 1/4 I might be able to get an adapter and relocate my oil pressure sensor there so I can put the temp probe in the filter housing.
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