Ok gentlemen, my 200F dodge stat came in and i swapped it into the truck. This experiment is based on comparisons of the 200F Mopar stat to the 195 Napa one. I decided to take the plunge in this, and will post up pictures later from my phone showing the two T-stats. The Mopar one is definitely looks Cummins to me, and is very beefy to start with. My Mopar one cost roughly 60 bucks out the door at the stealership, im sure one can find one cheaper elsewhere. I'll also grab a part number, but there is another thread somewhere on CF that lists it. Its a 6 series though. I decided that since no one else will play with this monster i should be the first. This is in reference to this thread here http://www.cumminsforum.com/forum/98-5-02-powertrain/579307-what-kind-thermostat-best.html So far, some baseline stats. Highway speed @ 65mph, temps 184-188, IAT 89-94 @ 45. GPD @ level, 2.40Gph(aproxx) Short idle, temps 184, IAT 105-114@ 45, GPH@ .74-.80 long idle , temps 179, IAT 96-105@ 45. GPH@ .80-.90 All units are in F. Also a short idle is say a stop ligt, to up to 7Mins. Anything over 5-7 Mins is considered a long idle. thus far today since i swapped it in, (and it burped), my temps are holding a stead 200-203F, idle gph was between .54 and .67! Thats amazing. Now we should also note that the scan guage that im using also is calibrated for the current running MPG. i expect this to change. I also took a short trip this afternoon. and we shall see over the next week or so how the temperatures handle. Tonight will be the first night of idling to say after i get to work, so we shall see.

Hey Im all for new ways to save on fuel!

Ok gentlemen, my 200F dodge stat came in and i swapped it into the truck. This experiment is based on comparisons of the 200F Mopar stat to the 195 Napa one.

I decided to take the plunge in this, and will post up pictures later from my phone showing the two T-stats. The Mopar one is definitely looks Cummins to me, and is very beefy to start with.

My Mopar one cost roughly 60 bucks out the door at the stealership, im sure one can find one cheaper elsewhere. I'll also grab a part number, but there is another thread somewhere on CF that lists it. Its a 6 series though.

I decided that since no one else will play with this monster i should be the first.

This is in reference to this thread here http://www.cumminsforum.com/forum/98-5-02-powertrain/579307-what-kind-thermostat-best.html

So far, some baseline stats.

Highway speed @ 65mph, temps 184-188, IAT 89-94 @ 45. GPD @ level, 2.40Gph(aproxx)

65 / 2.4 = 27.08 MPG ???

Short idle, temps 184, IAT 105-114@ 45, GPH@ .74-.80

long idle , temps 179, IAT 96-105@ 45. GPH@ .80-.90

All units are in F. Also a short idle is say a stop ligt, to up to 7Mins. Anything over 5-7 Mins is considered a long idle.

thus far today since i swapped it in, (and it burped), my temps are holding a stead 200-203F, idle gph was between .54 and .67!

Thats amazing. Now we should also note that the scan guage that im using also is calibrated for the current running MPG. i expect this to change.

I also took a short trip this afternoon. and we shall see over the next week or so how the temperatures handle. Tonight will be the first night of idling to say after i get to work, so we shall see.

You might actually do some video so I can see GPH, MPH, and MPG numbers...

As for my 65 MPH speed I would see roughly 3.61 GPH or roughly 18 MPG... Then my 55 MPH is roughly 2.5 GPH at roughly 22 MPG... So I would say you slightly off somewhere...

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Ok guys, so due to the fact my scan gauge was off by over a gallon when i filled up the truck today i consider my GPH figures completely wrong.

However i can tell the fuel economy is there just my the amount of driving 121 miles, and the fact that the SG told me i burned like 6.5 gallons of diesel, which seems about right for the gauge.

My last 10 fill up's list my avg mpg at 15.58mpg, with a tank high of 18.1, and a tank low of 12.2.

If i add up just the last 6 fill up's (that were not drag racing), i avg 15.88. With a low of 15.0 and a high of 16.3.

This last tank i netted 16.2 on 277 miles, 121 of which were spent with my new 200F t-stat in.

Now for the good news. my t-stat cycles between 198-202F in the truck IAT's were much warmer then before.

Now for the best part!. I was at the exe's this morning it was cold out about 30F. I pulled up to idle down and her bed room is about 30F from the street where i was, she heard my truck but it was quieter, but she said when she got to the living room she couldn't hear the truck anymore, that is right, for once she couldn't hear me! (in the living room)

I also could tell it was quieter as well when i opened the door, this thing really quiets down above 198F.

Also a note of CAUTION! I did some testing with the heating system today, and my heater system on MAX AC with the heat on high and to the max was putting out air in the 175-180F range according to my temperature gun, i will shoot this again tomorrow from a different angle to confirm, but it felt so nice to be warm for once when its 30F out.

Tomorrow i will perform this test here for a comparison, it says no more then 40F lower.

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/27-hvac-heating-ventalation-and-air-conditioning/86-heater-performance-diagnostics

But from experience i know that before the most i could ever get from my trucks heating system was maybe 150 on max ac. this is most interesting.

Well guys, an update.The scan guage has intermitent non connection issues,for example yesterday and two days ago the SG wouldn't turn on when driving, so i know that it will be off.I can say that my MPG is better, i hit 7/8's of a tank @ 80miles, which is better then 17 mpg. Then i went an ruined it the other day with some real localized stuff, and some lead footing. but then i got back on track after i was done that.The biggest plus is the cab heat, i can't say enough how i love it been 20F out and i can have a warm windhsield and a warm cab. I wouldn't think 10F would make this much of a difference but it does.As for the MPG well see, i have been driving like i normally do, and have seen an increase even if its not overall.

So guys, this thread has been quiet because im waiting to fill my truck up.To put it frankly, i filled up on 3/14, and now its the 21 and i still have diesel left :cookoo:This is very good since tomorrow is pay day, and i have 11 dollars in checking, lolI have added 420 miles on the odometer, and im between E and 1/8 tank, which translates to 21-24 gallons of diesel burned.I will add another 60 tonight roughly before filling up, so my ending mileage should be close to 500. Now this tank was not all mpg either, i had some rough driving, i towed a boat (only about 4,000 lbs), and picked up a load of firewood as well. I must be on crack because the numbers are showing a 2mpg overall gain from what i normally see. The fuel economy on fuelly has been accurate lately, since i started doing it, and we will see tomorrow what i will have for a total.

(No comment...)

Hard to believe if this is real. Just up the temp thermostat 10 degrees and pick up 2 mpg. :think:How are you at picking lotto numbers? I could use some help. :pray:I'm still following.

Pepsi is up in the frozen north like myself and what is occuring is the extra 10*F is aiding in heat the intake a bit more because he's showing a roughly +60*F offset on IAT roughly now between the winter front and the 200*F thermostat. Which tends to follow the same rules of effect with the MPG fooler as well. Except he's using actual IAT temps and no fooler. Also he's crossing the 100*F IAT mark which is the starting edge of MPG climb typicallly all the way to 140*F roughly.Which still means that cold air is not a friend of MPG's...

I had a Napa thermostat 190 and went to a cummins. My temp gauge gets up to 190, but it doesn't hold 190. When I coast it goes down 10-12*. I attribute This to cool temperature. 35-50 mostly lately. It's like it won't get up to operating temp unless you drive. Won't do it idling. I may install a cummins 200* next fall, but spring is right around the corner and will need the summer thermostat again soon.

My scangauge does the same thing with connectivity every now and then. I think its in the plug not the OBD port because my Smarty fits nice and snug while the scan gauge leaves a little to be desired.The biggest thing that helped my heat was putting on wint,er fronts a few winters ago. I hated driving my truck prior to that it would literally take 20 miles of driving before the heat was even halfway decent but never felt really warm unless I drove a long distance like maybe. 50+ miles or was towing something. With the fronts on the temp comes up within 5 to 7 miles (this is all country road driving no stop and go) and my temp will maintain 180 to 183 if Im on a flat road. And the heat will roast my eyeballs right out of the sockets lol

my temp will maintain 180 to 183

Geez... Another failed thermostat this is so common. If I can't maintain 191-193*F coolant temp on -25*F day without winter fronts I change thermostat's. I never use the winter fronts to compensate for a failed thermostat but to keep more heat under the hood for the engine.

Geez... Another failed thermostat this is so common. If I can't maintain 191-193*F coolant temp on -25*F day without winter fronts I change thermostat's. I never use the winter fronts to compensate for a failed thermostat but to keep more heat under the hood for the engine.

Its always ran around that temp as long as Ive had it and Ive been through 3 stats. My 2000 was very similar. They both BARELY run 190 in the dead of summer, so Ive chalked it up as "It is what it is". Throwing money away in thermostats isnt going to solve anything, other than lightening my wallet up.

Where did you get this 200F stat? I've only seen the crappy 180's and a 205 which I can't find at all.

Where did you get this 200F stat? I've only seen the crappy 180's and a 205 which I can't find at all.

200*F thermostat is from 6.7L 2008-current Cummins.

Where did you get this 200F stat? I've only seen the crappy 180's and a 205 which I can't find at all.

I think at the same place you got the 200* avatar:pant:. I saw one listed on Rock Auto for an 08. But I cant find one at the parts store. I went to the dealer in Terre Haute and they were no help at all. It took 10 minutes to tell me what temp the one for my 02 was.

Just tell the part counter you want a 2009 6.7L thermostat...

Well i couldn't get the mopar forum to post the other day so i held off until i could. I just copied what i wrote on CF.

Well guys, i was torqued as to weather to fill up yesterday, or today, and i decided to go for the 500 Mile mark. I filled up this morning at 500.1 on the trip, and at 29.19 gallons. When exact numbers are thrown i got 17.18 Mpg.

Yes a solid 1mpg. However i have collected data for about 8 days now on this new t-stat and i'll upload videos with time.

So far, the avg temperature is between 197-202, The IAT's @41F are 94-96, the coolant was also running in the 200 Range.

last night it was 30F out, and my IATs were averaging 85-87F out, and coolant was between 198-202F.

Earlier in the night the truck was still warming up, @186F the IAT's were 76F.

So here we can see where its 30F out, the difference in IAT's is about 10F between 186 and 200F. This video also shows the warm up from 186F to 206F, then when it settles you see IAT's then rise and level off.

Then this morning it was 25F out, and i shot a video(main to prove to you guys thatt he draw straw when CUT CORRECTLY will not give you issues:ban ghead:

Anyways my IAT's were a steady 81-83F, coolant held steady at 200F as usual.

I should have some videos uploaded in a bit, im combing through them to find the videos, and cutting out other non cummins related stuff

Hard to believe if this is real. Just up the temp thermostat 10 degrees and pick up 2 mpg.

How are you at picking lotto numbers? I could use some help.

I'm still following.

I can believe it now, i drove my truck to work Friday night and back and the SG was reading 18.8, the SG's fuel consumption seems about right so i divided it out against the ODO and it seems about what the SG reads.

For me from 1 to 7/8;'s is about 4 Gallons (about 3.75 To be exact), and i divided it out by 79.8 (trip) Either way i slice it im landing between 18-20 MPG, so i'll see what i get come empty again. hopefully i can exceed my 500.1 MPG on this tank.

I had a Napa thermostat 190 and went to a cummins. My temp gauge gets up to 190, but it doesn't hold 190. When I coast it goes down 10-12*. I attribute This to cool temperature. 35-50 mostly lately. It's like it won't get up to operating temp unless you drive. Won't do it idling. I may install a cummins 200* next fall, but spring is right around the corner and will need the summer thermostat again soon.

It sounds like what both of my older t-stats were doing, i replaced the older one with another one that was bad from NAPA, so then i read about the 200F t-stat and decided to try it.

My scangauge does the same thing with connectivity every now and then. I think its in the plug not the OBD port because my Smarty fits nice and snug while the scan gauge leaves a little to be desired.

The biggest thing that helped my heat was putting on wint,er fronts a few winters ago. I hated driving my truck prior to that it would literally take 20 miles of driving before the heat was even halfway decent but never felt really warm unless I drove a long distance like maybe. 50+ miles or was towing something. With the fronts on the temp comes up within 5 to 7 miles (this is all country road driving no stop and go) and my temp will maintain 180 to 183 if Im on a flat road. And the heat will roast my eyeballs right out of the sockets lol

I have a winter front on as well. But my heater system would take forever to warm up.

Where did you get this 200F stat? I've only seen the crappy 180's and a 205 which I can't find at all.

i got mine from the dealer P/N 68067109-AB.

Just tell them you need it, lol, my dealership never asked for a Vin Number.

Are you doing anything to counteract the fan settings for the OEM thermostat?I don't see it being an issue is winter, but in the summer you may lose mileage from extra fan use.

i have to ask mike when the fan clutch engages, but thus far i have not seen any issues as such.