Community Forums

dkacp · 06-17-2007, 04:14 PM

What are realistic expectations for the life of these conversion MDT haulers in terms of miles. Specifically interested in the 91 Chevy Kodiak 4500 and 5500 series but info on similiar models desired as well.
thanks, david and kelly

BronzeOwl · 07-29-2007, 07:14 AM

IMHO the engine makes a lot of difference. Is it a gasser or a diesel. When I have checked on diesel MH's, they don't even bother with the mileage. For the C5500, Four Winds puts the 8.1L Vortec Chevy in their gassers and the 6.6L Duramax in their diesel.

Typically, MH's only see 5 to 10 thousand miles per year, so a lot of people don't worry about too much mileage. Actually, too little mileage hurts them more.

bstark · 08-22-2007, 04:13 PM

This forum doesn't see a lot of activity so let's git'er go'in!

Here comes a cat for the pidgeon pile: There are 2 classes of MDT drivetrains and for want of better descriptors I'll simply use the terms "light-duty" and "heavy-duty".

Light duty: Chev & Ford short stroke higher rpm V8 diesels.

Heavy duty: Cummins, Caterpiller, International & Mercedes engines used in Freightliner, Peterbuilt and International MDT's

You will notice I left out the Cummins 5.9 and up engines used in Dodge's as they are a relatively lower rpm torque producing long stroke 6 cylinder engine and I would give them a higher rating for longevity than either of the V8 offerings.

I make my assumptions based on the higher piston speeds of the V8's associated with their inherant inability to develope meaningful torque until they are in a higher RPM along with the need to use rear ratios of 4:10 and up into the 5's when coupled with a double overdrive Allison to achieve the ratings for towing associated with the 4500 & 5500 series trucks. Variable vane and additional turbos to help alleviate the torque deficit are merely introducing another failure prone area and it is reliable longevity we're looking for, right?

Ever increasing emissions requirements are dictating the need to make these smaller diesel engines run closer to their design limits to achieve the same result their older counterparts were with less stress.

O.K., I got my flame suit zipped up, let 'er rip!

Dwayne & Danette · 08-22-2007, 05:42 PM

Bstark
well said,, we have a few F450's and some FL70 frightliners.. This is what we think of them..
WE use these trucks for oil field hauling.

Ford F450's poor fuel mileage 5-8mpg and we find we couldn't put much more wt. for hauling
High RPM and rear ends (POOR Mileage)

For a lil more money you can get:
FL 70 MDT Great fuel mileage 12-15mpg 250-300hp CAT. ( one pushing 700,000miles)

Jestme13 · 08-29-2007, 06:53 AM

Very good points of view, longevity also corolates with piston travel per mile, ft/mile.
This is why HD truck industry has never stayed with a V8 config, and that they are not good torque producers. I agree with bstark, this new wave of V8 consumer diesels are to the wall. I wonder what will happen once the after market starts to boost the heck out of them

dchasteen · 02-24-2009, 02:12 PM

In our experience, handled with good maintenance, there is no reason the MDT (Frtln, Pblt, Int'l) shouldn't get a minimum of 300,000 miles before an in-frame overhaul.

gearman · 05-16-2009, 01:55 PM

Quote:

Originally Posted by Jestme13

I wonder what will happen once the after market starts to boost the heck out of them

Where have you been!!!! Aftermarket has been "Boosting" V8 diesels for 20 years!!!

I know many that have put 300k miles on a international 7.3L v8 diesel, a few with 700K miles.

Larry · 05-18-2009, 08:52 PM

Yep, they have been boosting the V8s for years, but you won't get the longevity with them like you would with the Cats, Cummins, etc.
Larry

Jerry · 05-24-2009, 02:11 PM

International states that the 530E engine in my 4700 MDT is good for 750,000 miles, with proper care. I use oil analysis through Blackstone Labs and at 152,000 miles, they state that my engine looks perfect as far as wear metals. The 530E is also a sleeved engine and can be rebuilt at a relatively reasonable price compared to the non-sleeved engines (AKA throw-away blocks). The so-called HD pickups, 450-550's, do not compare. I know.....been there, done that!
Jerry

Link · 07-21-2009, 08:05 PM

The F-450 & F-550 have the SAME engine and the SAME trans. as the F-250 & F-350. They will also probably not last as long as the F-250 or F-350 as they will most likely be pulling a bigger load. Going for a class 6 MDT is a smarter move. And it will outlast several pickups and have a much better resale value.