Deltas while pulling

[Fosterslaw77]

Ok little lengthy but here it is. 2 months ago I drove to NC and back pulling my bike in an enclosed trailer. Weighing about 2500 lbs total. I saw deltas of up to 15 on occasion using Mobil 1 5w40 synthetic. Average deltas were 7-13. This week I made the same trip with a new trailer I went to pick up in Georgia. Empty I was seeing an average of 6-10 deltas. Basically oil temp stayed within one to two degrees it was collant temp changing mostly during whole trip. This is with rotella 10w30 T5. On way back I saw and average of 12 deltas. With a short peek of 14 on one hill on 81 in NC. This same hill two months ago I saw a 20 degree split with other oil. The only difference is the oil and the trailer was a new one that weighed 2250 with no wieght in it. So not much different in weight this trailer is much larger, and obviously was empty. Drove at night both times and temp was the same down there as I got north obviously it got cooler and truck ran cooler. Up here I was seeing about a 9 degree split and it was 31 outside. So question is is this thinner oil better to use? The heaviest I tow is about 6k so is it ok to use it during summer as well. I did see almost a mile per gallon difference as well on the plus side. Funny thing is with the T5 I initially saw my deltas rise 2-3 degrees empty but towing they were a bit better. Almost like the oil gets to a certain temp and doesn't fluctuate to much, and it may transfer heat better in the cooler cause its thinner. Anyone care to add thoughts on this? Thanks josh.....2006 f350 4 inch turbo back everything else stock with a coolant filter.

[Texas Wellman]

My truck has a service body so it is always loaded. I replaced my oil cooler and have a coolant filter with ELC. The EGR is fixed also.

I run anywhere from 10-15* delta on flat roads. I don't know if this is good or bad but it is what it is. Mostly I care whether the temps peaks and stays constant. When my cooler was plugged the temp would increase as long as you were driving.

I would like to see what others are seeing with a heavy load.

[DEVERO2]

As far as I know Deltas while pulling dont prove the oil cooler is blocked. Unloaded on flat road at 60 mph at operating temps is the best way to check deltas

[Six0~Stroker]

^^ That is correct. unloaded is the "way" to test the deltas. It is a fact that the deltas will increase with a load.

But not everyone can take that load off their truck. (service body trucks) so IMO and in my experience towing my deltas stay around 8-12*
so in that area I would not worry about it.

Unloaded and going 60 mph, my deltas are 2-4*.

[jd4010]

When hauling our 16K# 5er, we usually see about a 12* delta unless we're going up a long/steady incline but afterwards, it drops back. In fact, I see my deltas about the same (maybe 2 degrees higher) when comparing hauling/pulling versus not.

You'll get a lot of variation and a lot of opinions as to what is a good delta. For me, I have a 10* delta when unloaded and it's fine because I also have a CC, DRW, long bed with a 4.10 rear and I'm always hauling a loaded portable fuel tank so my gross weight is not the same as someone with a 250, short bed, SRW, etc. Both my coolers are new and I'm running ELC with a filter so I know they aren't plugged. So keep in mind that you need to compare somewhat apples to apples rig wise.

However that said, I think most everyone does agree that if you are running unloaded at 60-65 MPH on flat ground that your deltas should be less than 15* but when hauling/pulling, that doesn't apply.

[DEVERO2]

Originally Posted by Six0~Stroker

^^ That is correct. unloaded is the "way" to test the deltas. It is a fact that the deltas will increase with a load.

But not everyone can take that load off their truck. (service body trucks) so IMO and in my experience towing my deltas stay around 8-12*
so in that area I would not worry about it.

Unloaded and going 60 mph, my deltas are 2-4*.

I wish mine were that close

[Snake]

As important as the temperature split are the actual temperatures. What are your ECT's and EOT's?

[Six0~Stroker]

Originally Posted by Snake

As important as the temperature split are the actual temperatures. What are your ECT's and EOT's?

Very True.
Just for referance for the OP, mine are 190/193ish empty
and 195/205ish loaded.