Mobil Delvac 1300 15w-40 with 8700 miles, 1995 Detroit Diesel 12.7L series 60 with 112,900 miles

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Dec 15, 2010
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San Antonio,TX
Today received this, the latest UOA for our 1995 DD12.7L 60series with 112,900k miles. Oil and filters were new 13 mths ago at 104,200 miles. Engine is in my 1996 Prevost bus/mh that weighs 41k to 51k #s, depending on what I'm towing (or not), going down the road at 65 mph. Avg mpg is 7.5

The oil in this report (#6) is Mobil Delvac Super 1300 15w40.The oil filters were Fleetguard # LF9620, their "Venturi Combo" design: https://www.cumminsfiltration.com/venturi .

Notice the report indicates 6 qts of "lube added". Engine doesn't burn any oil. But, last summer the reserve oil tank site tube started leaking. Oil in the engine sump at that time was too new to be discarding. I drained 6 qts out of the engine to make room for the 6 qts of new oil from the reserve oil tank.

Report looks pretty good to me. Oil viscosity is thinning a little. Starts life at 13.9cSt and is now at 12.9 cSt. 40wt norm is 12.5cSt to 16.3cSt.

I don't always change the oil when I take a sample. I wait to see what the UOA report indicates then usually go a few more thousand miles before changing it. As you can see, I'm changing it way early.

Report #1 oil was 80% Amsoil 10w-40 HDEO and 20% Rotella T-3 15w-40 HDEO.

Report #2 & #3 was the same load of oil, 90% Delo LE 15w-40 and 10% Rotella T-3 HDEO.

Reports #4, #5, and #6 were for different loads of 100% Mobil Delvac Super 1300 15w-40 HDEO

What say you?

96 Liberty UOA 11-22.JPG
 
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Joined
Jun 28, 2017
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I've been following your posts on your DD in your Prevost. I've wondered what the GCWR is on your machine. I'm assuming the engine is rated to haul a lot more weight but the Auto Transmission maybe not up to more than 50K? Just wondering. The wife & I have rolled in a truck camper for the last 8 years. We went from motorhome, travel trailer, then TC... Backwards ha ha

Either way, it looks like the 1300 could have double the mileage easily! Thanks for the Post
 

jetman

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Joined
Dec 15, 2010
Messages
686
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San Antonio,TX
I've been following your posts on your DD in your Prevost. I've wondered what the GCWR is on your machine. I'm assuming the engine is rated to haul a lot more weight but the Auto Transmission maybe not up to more than 50K? Just wondering. The wife & I have rolled in a truck camper for the last 8 years. We went from motorhome, travel trailer, then TC... Backwards ha ha

Either way, it looks like the 1300 could have double the mileage easily! Thanks for the Post
The engine is DDEC3 (no wastegate) 470 hp. Trans is an Allison B500
Later model 12.7L Prevost had DDEC4 engines with up to 515hp (wastegate, variable geometry turbo) and the same Allison B500
Prevost eventually put 14L 60 series 550 hp with the B500.

Ours weighs 41k #s w/2 paxs, half fuel, half fresh water
We often tow 4 down a 4.5k # vehicle, so 45.5k #s. No difference in fuel mileage
or
a full 13.5' height all aluminum racecar stacker trailer that weighs10k lbs loaded. MPG drops to 5.5 (height=drag)
or
a normal height steel enclosed race care trailer weighing 8k #s. MPG 7.0
 
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Jun 5, 2003
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Apple Valley, California
I've been following your posts on your DD in your Prevost. I've wondered what the GCWR is on your machine. I'm assuming the engine is rated to haul a lot more weight but the Auto Transmission maybe not up to more than 50K? Just wondering. The wife & I have rolled in a truck camper for the last 8 years. We went from motorhome, travel trailer, then TC... Backwards ha ha

Either way, it looks like the 1300 could have double the mileage easily! Thanks for the Post
The engine was one of the best built and we're very common in semi trucks. They pulled 80,000 every day. Sometimes even heavier.
 
Joined
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Messages
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The engine is DDEC3 (no wastegate) 470 hp. Trans is an Allison B500
Later model 12.7L Prevost had DDEC4 engines with up to 515hp (wastegate, variable geometry turbo) and the same Allison B500
Prevost eventually put 14L 60 series 550 hp with the B500.

Ours weighs 41k #s w/2 paxs, half fuel, half fresh water
We often tow 4 down a 4.5k # vehicle, so 45.5k #s. No difference in fuel mileage
or
a full 13.5' height all aluminum racecar stacker trailer that weighs10k lbs loaded. MPG drops to 5.5 (height=drag)
or
a normal height steel enclosed race care trailer weighing 8k #s. MPG 7.0
The engine was one of the best built and we're very common in semi trucks. They pulled 80,000 every day. Sometimes even heavier.
Yeah, that's what I was thinking. The engine would of been put into some HD Semi's but the B500 transmission info I just googled on wikipedia is claiming the B in Allison B500 stands for "Bus". Interesting but that would also be why it wouldn't survive very long doing 80000K since it's obviously not rated for that. Still those Prevost are some the most hardcore motorhomes.
 
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RI
That series 60 will outlive the RV. One of the best engines ever made (with no EGR/DPF).

You’ll probably never have to worry about (from mileage you put on) but the bull gear has been the only issues with those motors. Keep an eye on the fuel dilution over time. If it gets too high may be time to have the injectors tested or replaced.
 
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