203 Tstat from Bob Riley

[hheynow]

hheynow, I thought the OBS had 203 stats, it was 99+ that Ford went to factory 195 stats. But what the heck do I know. Personally, I don't have a problem with the OBD guys chiming in.

Dennis

Ford changed waterpumps during the '96 production year. Prior to the change they came with a 203* and after with a 195*. The dieselsite 203* will fit the 7.3L mid-'96 model year forward.

 

[Snowman269]

Ford changed waterpumps during the '96 production year. Prior to the change they came with a 203* and after with a 195*. The dieselsite 203* will fit the 7.3L mid-'96 model year forward.

Yep, Thanks!

 

[CPUNeck]

Snowman, I think the 203* shouldn't really be viewd as a mod, but more of a "correction" . On the mileage I would consider perhaps your fuel stations have switched from winter blend. The engine should run more efficently, but 4mpg... seems a bit high for a slightly higher engine temp.

 

[Snowman269]

Snowman, I think the 203* shouldn't really be viewd as a mod, but more of a "correction" . On the mileage I would consider perhaps your fuel stations have switched from winter blend. The engine should run more efficently, but 4mpg... seems a bit high for a slightly higher engine temp.

Heh, Heh... I knew someone would say that, I was trying to avoid being longwinded on my post. None the less, coming from an WVO rig, it's a compliment. BTW, I've been searching for answers to storage on my rigs & your system is a well planned & constructed setup. I have many questions for you.

Back to the stat: I have documented every fillup for both of my trucks since new and you can track the fluctuations with winter blended fuel. Both of the stations "Pickleman's Truck Stop" in Newberry, Michigan & "Cenex Truck Stop" in Detroit Lakes, Minnesota have switched to straight #2 for the last 3 runs. I've talked with my wife about putting all the data into an Excel spreadsheet, she hasn't bit yet.

The reason I'm so excited is, the Excursion has NEVER EVER gotten this kinda mileage compared to the F250 on the same run at the same time, not once. I do believe I have an advantage to most diesel junkies, because I have 2 rigs to compare with back to back. I usually mod the F250 1st & if I see results, then I do the X. Side by side, this mod (fix of OEM mistake) has been the best dollar for dollar money I've spent on these things.

Hope that clears things up.

Dennis

 

[Dale_Lakin]

Im pretty sure the International trucks use a 203* stat. Problem is, Ford changed the waterpump design, and the international 203 stat wont work in our pumps. So Bob went out and had a new 203 built just for him.

At least thats the story I got.

Hmmmm I have a Navistar T-stat and a Ford one for the respective years and the stem is the same length on both???

 

[hheynow]

Side by side, this mod (fix of OEM mistake) has been the best dollar for dollar money I've spent on these things.

Yeah it's a good mod, but dollar for dollar I would be way ahead if I swapped a 3.55 for my 4.10 rear.

 

[Crumm]

Hmmmm I have a Navistar T-stat and a Ford one for the respective years and the stem is the same length on both???

Until 1996, all 7.3L Powerstrokes that were manufactured used an International water pump and an International short stem 203º thermostat . In 1996, Ford changed to a lower degree 195º thermostat. They changed water pump designs at this time as well. The new pumps required the new long stem 195º thermostat in place of the short stem to properly seat the bypass disk. All 1996-2003 Ford PSDs now come equipped with a long stem 195º thermostat. What year were you comparing? The 1996-up have a longer stem than the 94'-95'. DONOT use the shorter shaft thermostat in a 96'-up because it will not shut off the internal pump bypass. This will cause inaccurate coolant flow direction through the engine.

 

[Snowman269]

Yeah it's a good mod, but dollar for dollar I would be way ahead if I swapped a 3.55 for my 4.10 rear.

Definately. 3.55 worked well in the OBS.

I thought about going to 3.08 in the Excursion for highway traveling, but wasn't sure about city stop and go driving, plus I'd better be ready for a BTS.

 

[Dieselmeister]

Snowman,

I just wanted to respond to this thread because of the great results that you acheived by changing thermostats...

I have had my mileage go down per tank for a while now and it has been bothering me.. So when I saw your post I figured what the heck... my truck has 115,000 plus on it and the stat has never been changed.

I ordered one from Bob along with the Billet housing... very quick and easy to change... maybe 10-15 minutes..

I concur with what you were saying about better mileage... I was seeing an average of 12-12.5 in town and 13-13.5 hwy... Well I had to make a run to Cali and back and averaged 14.66 mpg ... It's not a huge gain but it made a difference.. And that's with my truck being lifted and running 37" tires.

I gotta say I am glad that you posted your results.. I would not have ever done the thermostat if you hadn't posted your results.. I will keep watching to see what my intown mileage does... I would be happy with 13..

As for the 203° mod...

 

[Snowman269]

Diesel Master, Great! I'm glad it worked for you as well! Again, my X seen big gains but the truck seen a smaller gain. I figure the truck was closer to optimal temps for good economy compared to the X.

I'd like to go 37's but the mileage alone would make it too expensive! It's a bummer that tires and a lift effect mileage so much!

In an equal comparison, the older gas engine trucks from the 80's and 90's would get 12-14mpg with stock tires (maybe). Your's is doing well when you look at those numbers.