PeachParts Mercedes-Benz Forum

PeachParts Mercedes-Benz Forum (http://www.peachparts.com/shopforum/)
-   Diesel Discussion (http://www.peachparts.com/shopforum/diesel-discussion/)
-   -   Coolant temperature and MPG's....Related?.... (http://www.peachparts.com/shopforum/diesel-discussion/304876-coolant-temperature-mpgs-related.html)

Josh8loop 09-08-2011 05:44 PM

Coolant temperature and MPG's....Related?....
 
Fellas,

Let me start by saying that I don't own a mercedes diesel at the moment. The last one I owned('86 190D) I sold a couple years back. I am currently courting a 1999 E300D and hope to be the proud owner in the future. I am very interested in fuel economy, and as such in the past I have experimented with higher than normal coolant temperatures and increased MPGs from the change. I am currently(along with 2 others) evaluating a "Hybrid" T-stat for my 2002 VW Jetta TDI. Stock temps for the TDI(ALH engine) is 195 Deg F, and I am now successfully runing between 203-209 Deg F with a 3-4 MPG improvement. The is a link to the Thread on the TDIclub.com so you can read a bit more if interested:

http://forums.tdiclub.com/showthread.php?t=306799


page 4 has some photos of the "Hybrid" unit, and some youtube videos of it's construction.




Since I now hope to have a E300D I wonder what the tolerance is to higher than normal temps on these? I see that the non turbo models ran 85C(185 F), and the Turbo units run 80C(176 F). I am somewhat unfamiliar with the OM606 cooling and oiling systems(though I am curently studying them) and am unsure if they would be able to support the higher temp(195 F) operation.

Specifically, do the 1999 E300D engines have piston skirt oil jets for piston cooling?

Also, how tolerant are the head gaskets, and heads to thermal warpage?



I know this topic can at times get heated:Pand very emmotional, but I'm just looking for some hard factual information you all may have(that is OM606 turbo specific) or have seen first hand. I realize I may get flamed for this type of heretical thinking. Thanks, and lookin forward to the discussion!



Josh

ready-ronnie 09-08-2011 06:48 PM

Two unrelated question
 
Its none of my business, but I would like to know about what you are going to pay for the 99 and its mileage. I have a 98 with 143k and I'm interested in what it is worth:confused:

Yak 09-08-2011 07:35 PM

I'm by no means an expert, but wonder about the specific temps used and rationale.

For example, the manufacturers may choose thermostats and temps that are a bit cooler than expected to compensate for unexpected conditions. They might want to stay away from 100c/212f in case someone runs water for some reason.

If the goal is higher MPG and if higher temps can get you there (more or less safely), are there other things that can complement it? Like blocking part of the radiator in order to reduce drag, or an electric fan with a higher set point so it stays off until a higher temp?

The linked thread starts off with warnings about oil temp. Would you add instrumentation to monitor that?

I believe you can improve mpg at the margins by some vehicle mods, but I think the biggest factor is still the right foot.

Josh8loop 09-08-2011 09:25 PM

Quote:

Originally Posted by Yak (Post 2787256)
I'm by no means an expert, but wonder about the specific temps used and rationale.

For example, the manufacturers may choose thermostats and temps that are a bit cooler than expected to compensate for unexpected conditions. They might want to stay away from 100c/212f in case someone runs water for some reason.

If the goal is higher MPG and if higher temps can get you there (more or less safely), are there other things that can complement it? Like blocking part of the radiator in order to reduce drag, or an electric fan with a higher set point so it stays off until a higher temp?

The linked thread starts off with warnings about oil temp. Would you add instrumentation to monitor that?

I believe you can improve mpg at the margins by some vehicle mods, but I think the biggest factor is still the right foot.



Don't disagree about the "right foot mod"-makes a huge difference. Aero mods can also be quite effective, although I still want to retain the cars full heat rejection capability so unless I create automatic adjustable leuvers I would need to leave it open. Your probably right on the coolant temps and the water issue.

On my jetta TDI I disabbled my low speed fans so they don't come on where they would have come on before(haven't noticed much MPG improvement from that). These mercedes use the mechanical clutch type fan(as far as I know?), so unless I were to add an electric fan I may not be able to gain anyhing there. Electric fan would be the way to go however IMHO. I'm thinking about running a 195 Deg F T-stat in the E300D, and that's not too far off stock temps(approx 10 degrees higher) anyhow.

Does the 1999 E300D use an air to oil heat exchanger or a coolant to oil oil heat exchanger?






..

EDBSO 09-08-2011 09:35 PM

Don't know about the temperature thing.
My MPGs are all over the place with city and highway. I am not a right lane driver, I like 8 to 10 miles per hour over the limit. I Have done some aero mods and others to come.

http://www.cleanmpg.com/garage/images/3509UK.png

http://www.cleanmpg.com/garage/images/cha3509UK.png

Josh8loop 09-09-2011 03:18 PM

Quote:

Originally Posted by EDBSO (Post 2787350)
Don't know about the temperature thing.
My MPGs are all over the place with city and highway. I am not a right lane driver, I like 8 to 10 miles per hour over the limit. I Have done some aero mods and others to come.

http://www.cleanmpg.com/garage/images/3509UK.png

http://www.cleanmpg.com/garage/images/cha3509UK.png



That's really cool! I will need to wait until I have the car to look further into aero mods. That will be fun to play with. If there are no technical issues to bumping up the operating temperature I would think I may see another couple MPG increase from just that change.


Some things that I will need to consider when changing operating temps:

-Transmission operates at the same temp(or really close) as the engine-
-the turbo OM606 may not have piston skirt oil nozzles/jets
-not sure how sensitive to oil viscosity these engines are
-not sure exactly how the piston rings will be affected(how much tighter they will get) by the slight temp increase
-cooling system components that are in marginal condition may leak or fail due to the higher pressures/temps. Will need to weed these out.
-clutch operated cooling fan would be engaged most of the time-may need a work around for this(electric fan?)




..

EDBSO 09-09-2011 10:48 PM

I am not at all certain but I believe that Euro E300 turbo diesels run a hotter stock thermostat. Perhaps 85C but am not at all certain.

Just found . . .
VALEO Part # 819970 Opening Temperature [C]: 85 Found at ********.com


Stock 80C = 176F

Available 85C = 185F

Likely a slight positive effect with very little if any negative results.

carnut 09-09-2011 11:05 PM

Just because you stabilize the temp 10 degrees higher with a different thermostat does not mean you've increased the pressure in the system. The pressure is determined by the radiator cap. The engine and oiling systems wont care if they're 10 degrees warmer. The mechanical fan clutch only works when the air flow is less over the radiator. So I wouldn't worry about it either. Running any engine hotter allows for less friction thus a slight potential mileage improvement. Removal of the fan clutch and installing an electric fan allows you to set the on temperature which means the engine will heat up quicker which MAY improve overall mileage.

Josh8loop 09-09-2011 11:29 PM

Quote:

Originally Posted by carnut (Post 2788172)
Just because you stabilize the temp 10 degrees higher with a different thermostat does not mean you've increased the pressure in the system. The pressure is determined by the radiator cap. The engine and oiling systems wont care if they're 10 degrees warmer. The mechanical fan clutch only works when the air flow is less over the radiator. So I wouldn't worry about it either. Running any engine hotter allows for less friction thus a slight potential mileage improvement. Removal of the fan clutch and installing an electric fan allows you to set the on temperature which means the engine will heat up quicker which MAY improve overall mileage.


Good input-thanks! I'm some what unfamiliar with the clutch fan operating characteistics so that helped too. Glad to see you didn't mention anything related to increased engine wear from the elevated temps-must not be a weak area of this particular engine. I'm kind of concerned about head warpage and head gasket failure. Not sure if that has been a major issue with these engines either? Thanks again!



..

Josh8loop 09-09-2011 11:39 PM

Quote:

Originally Posted by EDBSO (Post 2788159)
I am not at all certain but I believe that Euro E300 turbo diesels run a hotter stock thermostat. Perhaps 85C but am not at all certain.

Just found . . .
VALEO Part # 819970 Opening Temperature [C]: 85 Found at ********.com


Stock 80C = 176F

Available 85C = 185F

Likely a slight positive effect with very little if any negative results.






I saw those options too. I found an Omix-Ada unit part number: O321710652 that is 195 Deg F and can be purchased here:

http://www.overnightautoparts.com/storefront/?sid=132512FC88A9&rid=132512FC88A9&N=9253+4294965871&Vi=11206 4294961021 1668&mk=Mercedes Benz&md=E300&y=1999&Nr=OR(AND(make:Mercedes Benz,model:E300,year:1999),AND(universal:1))


Question I have about it is will it for sure fit the OM606, and does it have the rear bypass disc section like the original has? That picture just doesn't show if it does of not. If it will fit, and has all the proper components it may be ideal for a drop in replacement for added MPG's.







..

carnut 09-09-2011 11:41 PM

Head gaskets are not a weak point either. A diesel's compression is at a minimum, twice what a gas engine is. Head gaskets rarely fail on their own. Most times something else in the cooling system fails which then leads to head gasket failure. Detroit and other countries went to higher temp thermostats and electric fans to get engines quickly up to temp, thereby reducing cold start high exhaust emmisions. One byproduct of that was slightly improved mileage. Most newer cars run between 195 to 215 F, diesel or gas powered. Most electric fans are commanded on just before 220 degrees. A 14 LB cap will protect from boil over up to about 250 degrees with no harm to the engine. The key to mileage and lower emmisions is a quick rise to normal engine temperature and that it remain stable within 10 degrees under almost all driving conditions.

Josh8loop 09-09-2011 11:48 PM

Quote:

Originally Posted by carnut (Post 2788189)
Head gaskets are not a weak point either. A diesel's compression is at a minimum, twice what a gas engine is. Head gaskets rarely fail on their own. Most times something else in the cooling system fails which then leads to head gasket failure. Detroit and other countries went to higher temp thermostats and electric fans to get engines quickly up to temp, thereby reducing cold start high exhaust emmisions. One byproduct of that was slightly improved mileage. Most newer cars run between 195 to 215 F, diesel or gas powered. Most electric fans are commanded on just before 220 degrees. A 14 LB cap will protect from boil over up to about 250 degrees with no harm to the engine. The key to mileage and lower emmisions is a quick rise to normal engine temperature and that it remain stable within 10 degrees under almost all driving conditions.





Question is how do I acheive 195-205 Deg F in this type of engine? Any drop in replacements that you know of? Thanks for the help!



..

Josh8loop 09-12-2011 01:02 PM

Any one have any ideas?



..

Josh8loop 01-23-2012 11:18 PM

Bump. I'm still interested in this topic, and am curious to get your input.

Brian Carlton 01-23-2012 11:46 PM

When I worked for Chrysler, they had a Diplomat running at 235F. with a high pressure cooling system. It got about 15% better fuel economy than the standard vehicle.

Never decided to go forward with a prototype vehicle because of durability and maintenance issues.

Suffice it to say...........the warmer you run the engine, the better the fuel economy.


All times are GMT -4. The time now is 10:20 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website