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Amsoil and 5.7L Hemi MDS


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17 replies to this topic

#1 jlcantor

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Posted February 22, 2011 at 02:44 pm

I have just acquired a 2006 300C and am considering running an Amsoil oil and filter in order to achieve annual oil changes. The Amsoil website lists their 100% synthetic as being able to do this but it does not appear to be available in the 5W20 that I gather the Hemi's MDS system absolutely requires. Is there any wiggle room here? Will one of the Amsoil weights actually work with the MDS system or do I need to use their Performance Plus synthetic and go only to a six month oil change interval?

Thanks,
Jeff

#2 Doug D

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Posted February 22, 2011 at 02:55 pm

As far as I know there is no "wiggle" room. My understanding is for the MDS to work properly you must use 5W-20 weight oil. I have a 2006 Hemi as well but it's the "truck" Hemi which has a little more hp than the MDS Hemi installed in the 300C and Charger RT. I've always used regular oil (no synthetic) and have had no MDS issues over 118K miles. Only engine issue I had was a faulty EGR (P0406 code) at 83K miles. Replaced it ($77) and no further engine problems.

#3 valiant67

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Posted February 22, 2011 at 03:35 pm

That is my understanding as well, 5w20 or no MDS function.

I guess that makes oil changes, like transmission fluid changes, only me or the dealer. I don't trust the chains who would put whatever oil or ATF they feel like in no matter what you specify. I've had more than one car come back to me where 10w30 was specified and 10w40 was used or vice versa.

Edited by valiant67, February 22, 2011 at 03:37 pm.


#4 jlcantor

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Posted February 22, 2011 at 03:45 pm

Thanks for the quick confirmation! Six months is still better than "normal" and allows me to schedule the changes for nice, mild weather spring and fall.

Jeff

#5 Magnum1

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Posted February 22, 2011 at 04:13 pm

I`m using 5-20 Amsoil right now on my 2010 Dodge Ram 5.7, runs very good and I`m also injecting Aptomax T-70 engine decarb witch keep engine carbon off and running smooth.

#6 thummmper

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Posted February 22, 2011 at 09:15 pm

so what is mds?

#7 Doug D

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Posted February 22, 2011 at 10:30 pm

Multiple Displacement Service. Essentially the computer shuts off 4 of the 8 cylinders for improved economy and emissions under light load conditions. Though the article below says it was introduced in 2005 in the Magnum and 300C, MDS was also introduced in the 2006 Ram 1500's. (I should know - I have one). To date MDS has only been used in the 5.7L Hemi. There is rumour it will also be in the 3.6L Pentastar V6 down the road.

http://www.asashop.o...09/techtips.htm

How Chrysler's Multiple Displacement System Works

Posted 10/12/2009
By Greg Montero

In 2005, the Multiple Displacement System (MDS) version of the 5.7L HEMI engine was introduced on the Chrysler 300C and Dodge Magnum. This engine can deactivate four of the eight cylinders, and operate as a 4-cylinder engine during periods of low load, improving fuel economy and emissions. The MDS provides the 5.7L engine the fuel economy of a V6 while maintaining the performance of a V8. The fuel economy improvement is estimated to be up to 20 percent, depending on driving conditions. The MDS operation, invisible to the driver, is fully integrated into the fuel injection system.

"In 2005, the Multiple Displacement System (MDS) version of the 5.7L HEMI engine was introduced on the Chrysler 300C and Dodge Magnum. This engine can deactivate four of the eight cylinders, and operate as a 4-cylinder engine during periods of low load, improving fuel economy and emissions.”

When the MDS engine switches to 4-cylinder mode, the powertrain control module (PCM) controls solenoids that manage special "dual mode" lifters, allowing the intake and exhaust valves to remain closed on cylinders 1, 4, 6 and 7. There is one solenoid for each cylinder (two lifters). The PCM also deactivates the fuel injectors for these cylinders when in the 4-cylinder mode.

The PCM will activate the 4-cylinder mode when the following enabling conditions are met:

*

Low engine load
*

1200 to 3000 rpm
*

Vehicle speed between 12 mph and 90 mph
*

Battery voltage from 9 volts to 15 volts
*

Oil pressure from 15 psi to 147 psi
*

Oil temperature greater than 120 F
*

Engine coolant temperature from 158 to 248 F
*

Ambient temperature from 14 F to 248 F
*

No throttle position sensor or MDS faults

The PCM deactivates solenoids one cylinder at a time in the firing order. If the system is "on" for long periods of time, such as a long flat road with no stopping, the system will return to the 8-cylinder mode approximately every six minutes to maintain engine temperature. The PCM will also unlock the torque converter before the transition, to minimize the effect on driveability.

The oil temperature sensor used for this system is a two-wire sensor, negative temperature coefficient, like the sensors for engine coolant temperature or intake air temperature (IAT). The PCM uses this input - along with oil pressure, load and rpm - to calculate oil viscosity and flow rate. This information is critical to MDS operation.

It's important to know this engine uses 5W-20 engine oil. If the wrong oil is used, fault code P1521 can be set, and the vehicle may show symptoms of a shudder - similar to a torque converter shudder - when the MDS system is activated and deactivated. Other symptoms may include MDS performance codes or engine misfire codes.


Some additional notes, in the Ram 1500 equipped with Hemi MDS will not activate when the transmission is in Tow/Haul or No Overdrive mode.

Edited by Doug D, February 22, 2011 at 10:39 pm.


#8 Gerry G

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Posted February 25, 2011 at 10:51 am

This website did a long term analysis of Mobile 1 and Amsoil (only 2 completed to date) and one of the findings
was that the Amsoil tended to increase in viscosity over the life of the oil and after 14,000 miles the viscosity
had increased from 5W30 to 15W40. If the lower viscosity is needed for MDS to function. Amsoil may not be the
first choice.

(website neptune.spacebears.com/cars/stories/oil-life?html)

Hope this helps,

Gerry G

Edited by Gerry G, February 25, 2011 at 10:52 am.


#9 zrxkawboy

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Posted February 26, 2011 at 09:19 pm

AMSOIL makes a 0W20. This is the same viscosity as a 5W20 when at operating temp, which is what the MDS wants. The 0W20 will simply flow better when cold.

#10 ygdude

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Posted February 28, 2011 at 01:15 pm

AMSOIL makes a 0W20. This is the same viscosity as a 5W20 when at operating temp, which is what the MDS wants. The 0W20 will simply flow better when cold.


I agree with zrxkawboy/Jeff's post. AMSOIL's 0w-20 should work for you. I admit though, as an AMSOIL dealer some folks tend to be leary of the 0W. But, at operating temps it is 20 weight (so is the 5W). If you live in the deep south (TX & FL) you could, "in theory", use straight 20 weight as the multi-visocity would never kick in.

You could use AMSOIL's XL 5w-20. It is rated for 10,000 miles in normal use.

Good luck.

#11 AC TC

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Posted February 28, 2011 at 04:18 pm

zrxkawboy- you dont hang around at bob ist the oilguy?
Anyway, hemis with mds are supposedly xW-20 engines but i havent seen any
engine that has run into to trouble and that is strange since many quicklubes just pour
that 10w-30 dino, cheapest avail oil in em.
But as many other has said, dont bother about the "x"w rating if you arent particulary
intrested in cold starts- really cold starts.

#12 valiant67

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Posted February 28, 2011 at 06:15 pm

Anyway, hemis with mds are supposedly xW-20 engines but i havent seen any
engine that has run into to trouble and that is strange since many quicklubes just pour
that 10w-30 dino, cheapest avail oil in em.

The engine won't fail on 10w30. You would just lose MDS. Many people don't even know when MDS is kicking in or not because the default is not to show any indication on the dash when MDS is active.

#13 ImperialCrown

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Posted February 28, 2011 at 06:54 pm

MDS is designed to be seamless in operation. That's the beauty of it is that it is invisible.
A special exhaust system hides any change in exhaust note when switching between 8 to 4 to 8 cyl operation. The thinner viscosity is necessary to allow the MDS deactivation/reactivation to react quickly.
The newer Hemi's, world engines (4-cyl) and the Pentastar have VVT (variable valve timing) which also require the use of 5W-20 oil for fast and positive VVT action. Cam phasing fault codes can be set with the wrong oil.

#14 AC TC

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Posted March 1, 2011 at 05:29 am

Doesent it throw a code if it cant get into MDS?
Or if its quiet, happy and doesent throw any strange codes- MDS is functioning?

And what does the quicklubes pour in em??????

#15 Doug D

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Posted March 1, 2011 at 06:05 am

Doesent it throw a code if it cant get into MDS?
Or if its quiet, happy and doesent throw any strange codes- MDS is functioning?

And what does the quicklubes pour in em??????


Yes, it will throw a code, but I'm not sure what it is.

Just another reason I don't patronize quick-lube shops. They tend to want to use the oil they've bought in large quantities (usually 10w-30) instead of what the manufacturer recommends - in this case 5w-20.

#16 zrxkawboy

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Posted March 2, 2011 at 10:23 pm

zrxkawboy- you dont hang around at bob ist the oilguy?


LOL...as a matter of fact I do!

#17 AC TC

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Posted March 3, 2011 at 05:06 am

LOL...as a matter of fact I do!

Me too
//AC TC

#18 zrxkawboy

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Posted March 3, 2011 at 06:57 pm

Me too
//AC TC



cool!


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