2nd Gen Non-Engine/Transmission 3600 mile trip milage report

[Whitmore]

Just got home from a long trip from central Wyoming to Corpus Texas and back, thought I might give a report.



The truck weighed in at 9040 with gear loaded and the wife and I, yes this truck is 8640 normally with no people in it so keep this weight in mind as the thing is heavy.



I drove 80 mph prolly 70% of the time the rest was between 70-75 mph



Note* 80 mph = 2050 rpm



Truck has 3. 55 gears and 19. 5 wheels 35" tall, comp box on 2x2, 275 injectors, I adjusted my ramair to maintain 70*to 90* at the intake horn. Winds were strong for aprox 1000 miles of the trip and snow conditions for 100 miles (Wyo Rocks!!!)



18. 1 mpg for the whole trip, I think this is great considering my speed and 60% of the miles were in the Rockies with hilly travel!



Cheers, Kevin

 

[College Cummins]

I would have to agree with you, that your gas milage is pretty good, considering the wind and hillls that you dealt with. It amazes me every time it gets real windy outside how much surface area these trucks have. I have got a couple of quick question for ya. I have an HO as well, but at 70 I am running 2000 even, and at 80 it is something like 2250, two has marks over 2000. When you put those 19. 5's on there, did you correct the speedo? And, does the tire size affect how the tach read, I would imagine not, but was just curious? I know that those 35" tires you have on there will bring down the cruise rpm's but was surpised by how much. 2250 vs. 2050 Thanks and God bless, James

 

[Whitmore]

James, yes I did do the speedo correction, I have set it with a GPS so it is on. The RPM was not effected from the larger tires, one other thing I like about my combo with the 6 speed is when towing I have the option of staying in 5th gear and at 65 mph it is 2200 rpm, I towed a GVW of 26,600 a few months ago and used 5th gear and there wasnt a hill around that made me downshift, true I wasnt in the mountains but there was still some pretty good grades.

One day I will check my milage at 65 mph and see what the best is that I can get. 65 mph is at 1650 rpm.



Cheers, Kevin

 

[College Cummins]

1650 in 6th?! Man, I wish that I could get that in my truck! My truck is absolutely stock, and at 65 I'm turnin' one dash below 2000, which is like 1875 or so. Now, how could those 35" tires not affect your ratio? I guess that I am lost. because, technically, would'nt, with a larger than stock tire, the driveshaft have to turn as often, because of the increase in the circumferance of the larger tire? So to keep the 3. 55 ratio, one would have to go to a ratio of like 3. 73 or 4. 10. Do you remember what you were turning when you had the stock tire/wheel combo? I have towed with it stock, and I just kept it in sixth at about 75 mph. I was going through West Virginia, and had to down shift a couple times, but nothing serious, of course what really ticks me off is that I didn't have gauges so I couldn't watch EGT's or boost or FP.

 

[Old Man]

Picture's

Kevin, checked your reader's rigs gallery for your 19. 5's. If you get a chance, post a picture. I'm running the 19. 5's with simulators. Still waiting for the aluminums from Rickson's. You were having EGT problems a while back. What housing did you go to that helped you out. I'm fixing to change turbos. PM me if it is not an inconvience. Thanks.

 

[Whitmore]

I need to upgrade my pics as the 19. 5's arent in there,



College Cummins, yes the 35" wheel does affect the final ratio, that is why my rpm's are so low, heck at 80mph I only see 2000 rpm.



Old man, I went with the 14cm housing and it helped out, I also found I had a boot off a bit on my intercooler alowing a leak, egt are in check now



Cheers, Kevin

 

[College Cummins]

Thanks alot, I want to put some 35" on mine, and was wondering how much it would affect my rpm's. Sounds like it would make it alot more liveable, this 2000 rpm's at 70 are for the birds. I'm glad that you posted, thanks again!

 

[lschultz]

If I would of known where my digital camera was when Mr. Whitmore was at the house I could of took pictures of his truck so you fellows could see. But as usual when I have a certain thing in a spot where I know where it is the wife comes along and moves it. So I question my daughter when she comes home about the camera and she goes right to the spot and says here it is. He does have a very sharp looking truck with the 19. 5s. Thought he would at least let me drive it. But I was wrong