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Old 05-30-2012, 12:25 PM   #15
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Originally Posted by jimbo16720 View Post
I've learned over the years that smaller isn't always better. If the engine works too hard it is worse than a bigger engine. Even with cars I had a 67 nova with a inline 6 cyl and swapped a 283 v8 in and it was much easier on gas and the engine.
I had a Monza with the 262 V-8, light car, pretty big engine in it. Going up the Columbia Gorge on the WA side and not babying it I got 27 mpg. My Honda Ody with the same size engine with all the economy stuff won't do that well and is much slower too.

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Old 05-30-2012, 04:19 PM   #16
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I have 28,000 pounds in front of 300hp/950tq and on 6% grades I tend to stabilize at 48mph. I would think at 42,000 pounds it would be much slower... 3rd gear for sure and maybe even down to 2nd.


The Green Machine -- 2000 Mountain High Coachworks Summit (Spartan chassis / Cummins ISC)
...and F-Troop: Fearghus, Fiona, and Frankie (Cairn Terriers)
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Old 05-30-2012, 06:47 PM   #17
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We gross out at 28K ( 31.5 when we tow) and have an ISC 330/950ftlbs. We have been over 12,000 foot passes in Colorado and spent most of our time in the mountain west. If you will be in the flat lands an ISB might be fine.

We traveled with friends with a newer Alpine with an ISL, on hills we were no match and his mpg was every bit as good as ours.

But remember, when it comes to pulling and pushing there is no substitute for cubic inches.

As far as mpg, IMO very few people see 10-12 mpg. I think the norm would be around 7-9, ISB, ISC, ISL. in the west.

Tom, Patty, Hannah "The Big Dog" and Abby Kat, Indianapolis, Indiana 2000 36' FDS 72232 Our Photos
We live out in our old van. Travel all across this land. Drive until the city lights dissolve into a country sky, me and you - hand in hand.
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