Modified Thermostat for higher MPG's...

SD26

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235F in the summer. But, as you can see, I'm running the Evans.
And that's the data I was looking for...

Hybrid 205 is in with new Evans NPG+, and I think the highest temp I had was 224F on my Scanguage. Last June was cooler than what it has been here this March in Wisconsin. We're taking a trip to Florida soon, and our forcasted highs are warmer than some in Florida...LOL! Not that the temps are bad in Florida, but what we're getting here is close to ridiculous.

Will be doing a fill up very soon...and I'm just now completing a 5th gear swap.
 

josh8loop

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And that's the data I was looking for...

Hybrid 205 is in with new Evans NPG+, and I think the highest temp I had was 224F on my Scanguage. Last June was cooler than what it has been here this March in Wisconsin. We're taking a trip to Florida soon, and our forcasted highs are warmer than some in Florida...LOL! Not that the temps are bad in Florida, but what we're getting here is close to ridiculous.

Will be doing a fill up very soon...and I'm just now completing a 5th gear swap.


I'm not sure I would be comfortable running those temperatures. Maybe since the Evans has a lower heat capacity per volume the amount of coolant the "Hybrid" T-stat allows to go through the radiator at a given temperature isn't enough to shed the heat. We have seen these higher temperatures twice now with the "Hybrid" and the Evans-we though it was in the "Hybrid" construction method, but I'm wondering if the standard coolant is the difference?
 

SD26

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I'm not sure I would be comfortable running those temperatures. Maybe since the Evans has a lower heat capacity per volume the amount of coolant the "Hybrid" T-stat allows to go through the radiator at a given temperature isn't enough to shed the heat. We have seen these higher temperatures twice now with the "Hybrid" and the Evans-we though it was in the "Hybrid" construction method, but I'm wondering if the standard coolant is the difference?
I would say in my experience the coolant.

We had similar experience in racing motorcycles, not that all organizations would let us run propylene glycol for coolant.

I'll throw in my simple two cents on how I understand it.

Water and water/ethylene glycol coolants have lower boiling points. Engines have hot spots. In those hot spots, the coolant boils, and those areas are now pretty much "air cooled". The coolant temperature remains "reasonable", and the engine feels hot. On a road race bike, we'd have an engine that felt "nuclear"...way too hot to touch, but the coolant temperature was below 200F (in that way, we'd be using distilled water only). On cool off laps, the bike might get hotter and then blow out coolant into an overflow bottle.

When we started using Evans, or even RV anti freeze, the indicated temperature was warmer, but the engine was pretty much touchable. Since the coolant would always be a liquid because of its boiling point, it was continuing to remove heat from the engine.


An observation... I haven't had my fan go on because of these temperatures. I was wondering if that was a problem with my fan, but when running AC, both fans are operating. So, the function is there, but does the operation of the radiator fan do so because of the radiator coolant temperature rather than engine coolant temperature?

I wonder if the low RPM nature of the diesel engine allows coolant to enter the radiator and remain there long enough to shed a decent amount of heat before re-entering.

On the other side, last year, on a hot day while sitting in some traffic, my A3 started to hit 200*F and above, and the fan came on and I could feel heat through the engine compartment.
 

alloutdoorsboy

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Has anybody else noticed that the "HOT" air blown through the vents doesn't seem as hot with the Evans?? Guess this is due to its lower specific heat capacity huh???
 
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SD26

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Has anybody else noticed that the "HOT" air blown through the vents doesn't seem as hot with the Evans?? Guess this is due to its lower specific heat capacity huh???
Can't say that that is my experience. I have placed hotter thermostats and Evans in two 7.3 Power Strokes and now my TDI.
 

josh8loop

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My last fillup(week ago approximately) netted 64.85 MPG for over 900 miles I had on the tank. It's crazy to think this thing has 173k miles on it and is just now giving it's highest FE numbers. I just did an oil change(after 13k miles) on this tank of fuel, so maybe I'll gain a bit there too.
 

SD26

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My last fillup(week ago approximately) netted 64.85 MPG for over 900 miles I had on the tank. It's crazy to think this thing has 173k miles on it and is just now giving it's highest FE numbers. I just did an oil change(after 13k miles) on this tank of fuel, so maybe I'll gain a bit there too.
That's awesome, Josh! Something for the rest of us to shoot for!

Just filled up. MPG was 49.4, and I have a .681 fifth. Last tank was 45.6. Both of those tanks I had the hybrid tstat with Evans. Previous was 52.6 using the 195*F tstat...but I had my snow tires on with stock steel wheels. The two lower tanks with the 205*F tstat included my change to the summer wheels and tires that came with the car...225/40's mounted on 18" alloy wheels.

So, sure, I guess I can give some away to the wheels and tires. I would like to measure some weights.

Still, I know that my coolant temperatures with the hybrid were 216F to 224F in some of our very reasonable weather as measured on my ScanguageII, while I don't believe yours, Josh, are reaching 216F very regularly at all.

We're leaving on a trip Friday/Saturday, and I think I will pull out the hybrid and put in the 198*F Wahler tstat that I have to the trip and retain the Evans coolant.

Gearbox oil is draining right now, and I will be refilling with Redline MTL.

Josh, on your CCV set up, where did you get your elbows?
 

josh8loop

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That's awesome, Josh! Something for the rest of us to shoot for!

Just filled up. MPG was 49.4, and I have a .681 fifth. Last tank was 45.6. Both of those tanks I had the hybrid tstat with Evans. Previous was 52.6 using the 195*F tstat...but I had my snow tires on with stock steel wheels. The two lower tanks with the 205*F tstat included my change to the summer wheels and tires that came with the car...225/40's mounted on 18" alloy wheels.

So, sure, I guess I can give some away to the wheels and tires. I would like to measure some weights.

Still, I know that my coolant temperatures with the hybrid were 216F to 224F in some of our very reasonable weather as measured on my ScanguageII, while I don't believe yours, Josh, are reaching 216F very regularly at all.

We're leaving on a trip Friday/Saturday, and I think I will pull out the hybrid and put in the 198*F Wahler tstat that I have to the trip and retain the Evans coolant.

Gearbox oil is draining right now, and I will be refilling with Redline MTL.

Josh, on your CCV set up, where did you get your elbows?


It will be interesting to see how that Wahler 198 Deg F T-stat does with the Evans. We know if it trends up to the 210 mark then the Evans is allowing the system temperature to rise slightly. Those wheels will definately reduce MPG's for sure as you know. The elbows I got for the CCV system I picked up at NAPA. They have a multipack kit in a tackle box full of plastic fittings. I did have to grind down the hose barb area slightly on the elbow that goes into the valve cover so it wasn't too tight on the VC grommet. BTW my CCV setup doesn't perform as well as the Mann-Hummel Provent system(since it doesn't have the internal glass fiber oil separator material), but is lots cheaper.
 

SD26

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It will be interesting to see how that Wahler 198 Deg F T-stat does with the Evans. We know if it trends up to the 210 mark then the Evans is allowing the system temperature to rise slightly.
Dropped the trans oil last night and replaced it this morning with Redline MTL. And I put in the 198*F tstat. Initial run had my highest temp at 202 with the ambient temp at 65*F while running Evans NPG+.

My intuition is that both tstats that I assembled have inconsistent results. Might be a problem on my disassembly and assembly.

Those wheels will definately reduce MPG's for sure as you know.
Yeah, I was hoping that it wouldn't be as bad as it appears, but they do look pretty sweet. I'll keep telling myself "they came with the car"...:D

The elbows I got for the CCV system I picked up at NAPA. They have a multipack kit in a tackle box full of plastic fittings. I did have to grind down the hose barb area slightly on the elbow that goes into the valve cover so it wasn't too tight on the VC grommet. BTW my CCV setup doesn't perform as well as the Mann-Hummel Provent system(since it doesn't have the internal glass fiber oil separator material), but is lots cheaper.
Cheaper is good while still being an improvement over stock. I'll see if I can get some elbows and maybe complete that by Thursday.
 

dieselfuel

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SD26,

You are aware the mileage gain with the Evans coolant is with the HDTC.... no?

I'm not sure one should use a higher than rated t-stat with any other Evans coolant.

The research Evans has conducted, was with the HDTC and a t-stat 20F higher than rated.

Just something to ponder.

df
 

williamgd2

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Ski in NC you are very knowlegable and correct. It has been seen over the years that there's been problems in that exact area especially with the diesle.Remember Mitsubishi's diesle pickup trucks? Are you guy's old enough? Problems with aluminum heads and head gaskets. The heat difference and different metals responding differentlly to the heat.I won't do it.
 

SD26

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SD26,

You are aware the mileage gain with the Evans coolant is with the HDTC.... no?
Actually, no, df I didn't know that...

I've used a number of the Evans' products over the years, and HDTC a new one to me. I've used NPG+ now in five vehicles for over quite a number of years. I can still find NPG+ with no problem, but it is no longer listed on the Evans' site. Doing a little searching, it almost appears that HDTC is the replacement for NPG+. Both are compatible with each other, but there is something in the additive package that allows HDTC to have increased mileage durability. Boiling points both appear to be the same. Do you know anything more on that?



Now, I can't speak for him, but isn't Josh using a standard water/EG mix?



Having a few miles on the current thermostat, the 198*F Wahler, my Scangauge coolant temperatures are a real solid 197-204*F. I'm honestly kind of amazed how it stays in the 198-200*F range. Given that I've used five thermostats now (what was in it, my first hybrid, a 195*F Stant, my second hybrid, and the 198*F Wahler), it really appears that when I use a hybrid, I have strange swings in temperature that I believe have to be related to my disassembly and/or assembly of the hybrid tstat.
 

josh8loop

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Actually, no, df I didn't know that...

I've used a number of the Evans' products over the years, and HDTC a new one to me. I've used NPG+ now in five vehicles for over quite a number of years. I can still find NPG+ with no problem, but it is no longer listed on the Evans' site. Doing a little searching, it almost appears that HDTC is the replacement for NPG+. Both are compatible with each other, but there is something in the additive package that allows HDTC to have increased mileage durability. Boiling points both appear to be the same. Do you know anything more on that?



Now, I can't speak for him, but isn't Josh using a standard water/EG mix?



Having a few miles on the current thermostat, the 198*F Wahler, my Scangauge coolant temperatures are a real solid 197-204*F. I'm honestly kind of amazed how it stays in the 198-200*F range. Given that I've used five thermostats now (what was in it, my first hybrid, a 195*F Stant, my second hybrid, and the 198*F Wahler), it really appears that when I use a hybrid, I have strange swings in temperature that I believe have to be related to my disassembly and/or assembly of the hybrid tstat.



Yes, actually I still use water/EG mix. I will however in the future(after I get a couple other coolant hoses replaced) be switching to the real VW McCoy. I've got to admit, I'm disapointed that we are seeing coolant temp swings with the Hybrid T-stat. It is good however that the Wahler unit does seem to be getting us slightly higher, and also has a good construction build quality-Glad Frankencar mentioned it to us.

I was hoping to try an experiment with the "Hybrid" units. I wanted to lengthen the rear section a bit by not pressing it on so far. I'm not talking about much of a length change maybe on the order of .020-.030". I am thinking that if you slightly lengthen the T-stat assembly, once the T-stat starts to open it will pinch off the rear bypass section sooner than it did before and will force more coolant through the radiator. In theory this will work, but in practice it would need to be proved out. I have been extremely busy at work, and my wife has some new urgent medical issues that are needing attention or else I would be trying it.
 

SD26

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...and my wife has some new urgent medical issues that are needing attention or else I would be trying it.
Josh, I think I read something about that not too long ago in an older threat, and I wanted you to know that you both are certainly in my thoughts.
 

SD26

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I've got to admit, I'm disapointed that we are seeing coolant temp swings with the Hybrid T-stat. It is good however that the Wahler unit does seem to be getting us slightly higher, and also has a good construction build quality-Glad Frankencar mentioned it to us.
I guess I put the temperature swings on me... Impatience, lack of attention to detail... I'm disappointed in myself, but I'm not done yet.

I was wondering if the TDI industrial engine would have a warmer thermostat since it might not have to conform to some emission standards of cars. Something that would be a drop in unit. Did some searching, but I haven't came up with anything as of yet.
 

josh8loop

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Josh, I think I read something about that not too long ago in an older threat, and I wanted you to know that you both are certainly in my thoughts.

Dave,

Thank you my friend :)
 

josh8loop

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I guess I put the temperature swings on me... Impatience, lack of attention to detail... I'm disappointed in myself, but I'm not done yet.

I was wondering if the TDI industrial engine would have a warmer thermostat since it might not have to conform to some emission standards of cars. Something that would be a drop in unit. Did some searching, but I haven't came up with anything as of yet.

I do recall some mention of a TDI industrial engine but I'm not sure it's any different from what we have now-could be the same animal? Worth further investigation. I was rather meticulous about the reassembly of my "Hybrid" units, but I don't think construction quality or reassembly quality is at play here. It really shouldn't be too difficult to do in the home shop-if it is then we need to figure out a better way of doing it. Perhaps create a way to adjust the length of the T-stat. That way one could do the initial assembly(matching the original stock Stant dimensions), install it and see where it operates. If it operates too hot or cold, it could be removed and adjusted slightly. have any ideas on that front?

For now the 92 Deg C Wahler unit sounds like a sure bet in the interim.
 

SD26

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Thanks, DF! Was on there again, and I couldn't find much that compares and contrasts the new from the old...other than the longevity.


We're on a trip right now... Going through Alabama, there was a huge accident or something, and the weather is really nice! Coolant topped out at 204*F. Still very consistent with most temps between 197-200 with lows of 195-204. (I really want to make a hybrid work...)

On the bad side, my cat broke off at the rear and is now hanging down. Cabin is a little louder but not unbearable. Decisions, decisions...recommendations solicited too... I'm thinking that I'll probably wire it up for the duration of the trip, and then do a more permanent fix when we get home.
 

Rual817

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cetane boost = better FE

Does anyone use Power Service injector Cleaner with cetane boost? And has anyone noticed better FE using it?
Here is what i noticed just recently. Couple weeks ago I was at Wally World geting a few things, thought while there top off (1/2 tank). I put 5oz. of PS in every tank (costs $1/ 5oz by the gallon). Not thinking I put a full 5oz instead on 2.5oz for 1/2 tank. Was getting 40.5 mpg, but that tank I got 43 (have not seen that # since). This was before I undestood about cetane levels with certain suppliers. Now I buy Exxon and thought I'd try to see if I could duplicate so I put 10oz. Normally I get 100mi before my mark leaves full, then 100+/ 1/4 tank. which translates to marking 200mi by 3/4 tank. This time I was @ 275 by the 3/4 mark. If this keeps up I may be around 45-48 mpg. Will let you know on next fill in a few days.
Anyone else use PS?
 

MikeMars

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Did you remember to add in the volume of the cetane booster onto the fuel volume? I.e., if you put in 30 litres of fuel & 1 litre of booster, that should count as 31 not 30.
 

Abacus

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Thanks, DF! Was on there again, and I couldn't find much that compares and contrasts the new from the old...other than the longevity.


We're on a trip right now... Going through Alabama, there was a huge accident or something, and the weather is really nice! Coolant topped out at 204*F. Still very consistent with most temps between 197-200 with lows of 195-204. (I really want to make a hybrid work...)

On the bad side, my cat broke off at the rear and is now hanging down. Cabin is a little louder but not unbearable. Decisions, decisions...recommendations solicited too... I'm thinking that I'll probably wire it up for the duration of the trip, and then do a more permanent fix when we get home.
This is pretty common. The best temporary fix I have seen involves some flat stock and some muffler clamps. Bend the flat stock so it goes from the pipe to your cat (following the contour), then use the muffler clamps to hold it in place.
 

SD26

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This is pretty common. The best temporary fix I have seen involves some flat stock and some muffler clamps. Bend the flat stock so it goes from the pipe to your cat (following the contour), then use the muffler clamps to hold it in place.
That was kind of the idea I was having too...

But a local muffler shop cut out a piece, added a piece, and welded it in for $50. No complaints!
 

SD26

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Anyone else use PS?
Yes. And I've used two cycle oil, used engine oil, vegetable oil, and other additives.

As much as I wanted to see a difference, my data said otherwise.
 

Abacus

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Yes. And I've used two cycle oil, used engine oil, vegetable oil, and other additives.

As much as I wanted to see a difference, my data said otherwise.

Your mileage may not see a difference, but the injection pump and engine might over the long term.

I add 1 oz of 2 cycle oil and 1/2 oz Power Service per gallon of diesel and always have. This was my uncleaned piston (albeit the best one, but all were pretty clean) at 393,000 miles when I replaced the head gasket.

I'm still on the original injection pump as well.

(click picture to enlarge)
 

josh8loop

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Your mileage may not see a difference, but the injection pump and engine might over the long term.

I add 1 oz of 2 cycle oil and 1/2 oz Power Service per gallon of diesel and always have. This was my uncleaned piston (albeit the best one, but all were pretty clean) at 393,000 miles when I replaced the head gasket.

I'm still on the original injection pump as well.

(click picture to enlarge)




That is amazingly clean. Could it be that coolant/water was being drawn in, and steam cleaning things a bit? Also, recently I was reading about fuel system lubrication and they have found that the addition of 2-5% addition of good quality BioDiesel makes a much larger impact on fuel system lubrication vs the 2-cycle oil FWIW.
 

Padrino

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Does anyone use Power Service injector Cleaner with cetane boost? And has anyone noticed better FE using it?
Here is what i noticed just recently. Couple weeks ago I was at Wally World geting a few things, thought while there top off (1/2 tank). I put 5oz. of PS in every tank (costs $1/ 5oz by the gallon). Not thinking I put a full 5oz instead on 2.5oz for 1/2 tank. Was getting 40.5 mpg, but that tank I got 43 (have not seen that # since). This was before I undestood about cetane levels with certain suppliers. Now I buy Exxon and thought I'd try to see if I could duplicate so I put 10oz. Normally I get 100mi before my mark leaves full, then 100+/ 1/4 tank. which translates to marking 200mi by 3/4 tank. This time I was @ 275 by the 3/4 mark. If this keeps up I may be around 45-48 mpg. Will let you know on next fill in a few days.
Anyone else use PS?
For the last 6 months I've been using a stuff that a friend brought over from UK, its call Miller Diesel Power Sport/ Eco Max. It is injector cleaner and bring the cetane level 5/6 points up effectively making it 52/53 instead of regular 47 claimed by the local garage . Using 0.25ml in a tank of fuel. The bottle is 500ml so you have cover for 20 tanks. The stuff is brilliant. Since I started using it my car runs much, much smoother, quieter, NO SMOKE AT ALL, even during the winter months, just a very small puff when you starting first thing in the morning and that's it. Now when the weather is getting warmer is running without any smoke even under a very heavy acceleration. My MPG went up by 5/6 miles under the same driving condition and driving habits. The cost of a bottle on eBay UK is around $20 bucks plus whatever is the shipping from the UK. Sound expensive I know, but one bottle is good for 20 tanks of diesel. If you start gaining even 4MPG, it will pay for itself in the first few tanks. On a tank you will get about 80 to 100 miles more, this is about 2 gallons of diesel, so you looking around $7,50/8 bucks. Even if you pay $30 including shipping it will cost you around $1.50 a tank, in my calculation this is a bargain.
He was here few weeks back again and I have few more bottles :D.

You can buy the stuff from UK eBay site. I am sure someone will post to the US.
If you do....DO NOT STORE IT IN YOUR CAR, the stuff smell not very pleasant but it works like a charm. Always use some disposable gloves when you putting it in your car. The bottle is with "smart" lid so you could measure the correct 0.25 ml before you go to your local garage for diesel.
This is a link for the UK parts store selling it:
http://reviews.halfords.com/4028/811125/reviews.htm

ebay
http://www.ebay.co.uk/itm/MILLERS-D...arts_Vehicles_CarParts_SM&hash=item5ad710ddee
 

SD26

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Even if you pay $30 including shipping it will cost you around $1.50 a tank, in my calculation this is a bargain.
One could put that same amount of money toward a hybrid thermostat and pay for the thermostat in just a few tanks and then bank the further savings or buy an additive...

This thread is about the concept of using such a thermostat, after all...
 

josh8loop

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SD26,

When you assembled your "Hybrid" T-stat, did you notice when you pressed the rear section on that it seemed a bit loose like you could have changed it's position by hand pressure alone? I'm wondering if the inconsistancy of temperature regulation is from the rear bypass disc changing it's position once in service. Remember when the T-stat increases temperature it's length is modulated according to engine temperature. At certain temperatures the rear section is pressed up against the round hole in the block, and if it's not pressed on tightly it may cause it to shorten some changing it's temp regulating characteristics.

The reason I ask is that I noticed when I was playing with some and assembling some that the rear press on sections on some seemed more loose than others. I ended up using a ball peen hammer and gently peen the copper material so that it pressed on a bit tighter than it would have otherwise. You want to get the overall length matched to the original stant 195 Deg unit, while making sure it will not shorten while in service.
 
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