High Mileage vs Synthetic High Mileage

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2009 Chrysler T&C, 3.8 engine. Vehicle was consuming oil at the rate of 1 quart per 1000 miles. Last OCI, I used Mobil 1 Synthetic HM. Consumption was 1 quart in 2000 miles. I topped off with Mobil Super HM. 3000 miles later, I was down about a quart. Again, I topped off with Mobil Super HM. About 700 miles later, I dumped the oil because I had left my oil cap off.

This OCI, I just used Mobil Super HM. Oil is down a half quart in 1000 miles. It has me wondering what is cutting the consumption, the "high mileage" or the "synthetic" portion of the oil. Previous oil changes with Mobil 1 and Pennz Platinum did not cutbconsumption.

When I am down a quart, I will top off with Mobil Super HM and see if the vehicle "adjusts" to this oil.

After that, I will reverse the oil change pattern and observe. Previous OCI was Mobil1 Synthetic HM with Mobil Super HM used to top off. This OCI will be Mobil Super HM with Mobil 1 Synthetic HM as top off. It just worked out this was because I didnt have Mobil 1 HM when I changed oil last.
 
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I had the complete opposite on my Dakota. Pennzoil yellow cut my consumption at least 50% from mobil 1 HM 10w30. Heck the pennzoil yellow bottle is even thinner 5w30. I'd bet it has less to do with syn vs dino and more the additive package of any given oil.
 
Try the least expensive of the 10w30 HM oils at Walmart. Only top off with the same brand. Run 2-3 5000 OCIs and keep track of consumption. Then decide.
 
Ambient temps also seemed to make more of a difference in my case. Hot weather reduced consumption. Why i don't know.
 
Originally Posted By: otis24


After that, I will reverse the oil change pattern and observe. Previous OCI was Mobil1 Synthetic HM with Mobil Super HM used to top off. This OCI will be Mobil Super HM with Mobil 1 Synthetic HM as top off. It just worked out this was because I didnt have Mobil 1 HM when I changed oil last.


Why would you purposely top off with something different than what's in the engine? How does this tell you anything meaningful? Why not go buy another quart at *gasp* full price if necessary and use the same oil?
 
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I think you have too many variables involved to say it is this or that. If it is burning that much I wouldn't pay extra for synthetic, but stock up on some Supertech instead.
 
I was able to cut consumption drastically on my previous oil change. That happened using Mobil 1 HM and topping off with Mobil Super HM. That combination saw a tapering off (2000 miles per quart) then a huge reduction (3000 miles per quart).

Mobil Super is probably one of WM's cheaper HM oils. Its looking like the Mobil Super HM will go at least 2000 miles per quart. Curious to see if it will drop off after that.

"Why would you top off with something different than what's in your engine?". Both being Mobil oil, they probably have similar additive packages. People here have been blending oil for years with no adverse affects. In my case, if this combination achieves a huge reduction in consumption at a reduced cost, why not?

The combination of Mobil1 HM with Mobil Super HM seemed to be working, but that "experiment" was cut short due to me leaving the oil cap off. I would have continued with the combination except for the fact that oil choices in my small town are limited and I did not want to go any further on that oil after I had discovered my error.

It will be interesting to see if the Mobil1HM/Mobil Super HM combination, in different porportions, performs the same or not. I can switch to Mobil 1 HM at any point, and top off with the same at anytime, should consumption fail to be reduced.
 
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Run a thicker oil. M1 0w-40 or Castrol 0w-40 here. Thicker oil almost always works.

Originally Posted By: Brybo86
Syn from the beginning and I bet you wouldn't have these consumption issues
Not correct. This isn't a syn vs. conventional issue at all.
 
I don't know what was used previously. I purchased the vehicle with 64k miles. I've used Mobil1, Pennz Platinum and Pennz Ultra. The first two had no effect on consumption. Ultra improved things only slightly over the other two. The high mileage oil has drastically reduced consumption.

Last OCI was my first usage of High Mileage oil (Mobil1 HM, with Mobil Super HM used for top-offs). Consumption was dramatically reduced.
 
Originally Posted By: AZjeff
Do you know the results of a run of straight M1 HM or M Super HM? Seems that would be the logical starting point, not that any harm is done by mixing.

But wait, this is BITOG. Nevermind!


No, I dont. Ive got Mobil Super in it now. Nothing lost if I run Mobil Super HM for about 6k. If the consumption doesnt taper off, I can switch to Mobil1 synthetic HM next OCI. That is probably the most logical course if action.

My bet is that Mobil1 HM will produce better results. It seems as if Mobil1 HM with Mobil Super HM as top-off oil was working. Perhaps using just Mobil1 HM will eliminate consumption all together.

Well, let the testing begin. I will run just Mobil Super HM this OCI and Mobil 1 HM next. OCI's will be a minimum of 6k, 9k if I have to top off frequently. If I get consistent consumptuon with the Mobil1 HM, I will go back to Mobil1 HM with Mobil Super HM for top off.
 
Thing is, oil consumption on these engines is b/c of issues with the way the rings are installed, it's not really b/c of wear in the engine.

Viscosity is the only real solution...whatever oil is thickest should reduce consumption the most.

In the summer I'd run a 10W-40 HM oil in whatever make you can find.
 
Originally Posted By: addyguy
Thing is, oil consumption on these engines is b/c of issues with the way the rings are installed, it's not really b/c of wear in the engine.

Viscosity is the only real solution...whatever oil is thickest should reduce consumption the most.

In the summer I'd run a 10W-40 HM oil in whatever make you can find.


I had heard that back when I experienced consumption with my 2005 Grand Caravan that I had purchased new. I find it hard to believe that an issue that was known back then, would continue to be repeated. In regards to thicker oil, I have tried topping off with 15w/40. Until now, nothing has worked to reduce the consumption of oil in this vehicle other than a High Mileage oil.
 
Update: im 2500 miles into the OCI with Mobil Super High Mileage 5w/30. Down 1 quart. This could be due to the van "adjusting" to this oil. We will see how the next few thousand miles go.
 
Run 1 oil brand and weight for at least 2 OCIs before coming to anymore conclusions. Top off with the same brand and weight only. Check PCV if applicable and look for leaks at the pan and gaskets.
 
2500 miles since last top-off using Mobil Super HM. Should easily go to 3k before I hit the ADD mark.when it needs a top-off, I will be about 5500 into OCI. I will just change it at that time. Seeing as how the vehicle has done well on a conventional HM, the most logical next step would be to go to a semi-synthetic HM. Mobil doesnt make a semi-syn HM that i am aware of. Based on price, i will probably use MaxLife semi-syn HM or Magnatech semi-syn HM.
 
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