I have read that a high temp thermostat can have a significant impact on gas mileage do to less wasted heat. My 2004 Civic has a 170(stock temp) thermostat in it now. What would the disadvantage be to a higher temp? Like 180 or 195? I read that a higher temp thermostat will reduce power. Is that true too?
Should I get a high temp thermostat?
- Thread starter Avery4
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Good God stick to the oem t-stats. Lots of problem reports on the Accord forums when using aftermarket t-stats. The Civic probably wouldn't be much different in that regard.
edit: found this:
Originally Posted By: ;774689
Aftermarket stats cause issues in Hondas and many other imports.
The guy on the Ody forum is incorrect. The stat is NOT fully open at 172 and his C to F conversion is a bit faulty. If his stat was fully open at 172 its no good.
The factory stat that Honda uses starts to open at 176 and is completely open at 194. Your factory stat could be opening early. You'll never see this on the gauge, as a "normal" reading is 140~220. If you have a scan tool, watching the ect is a good way to know if you have any bleed thru the stat, it should come rather quickly to temp, maybe 5 minutes max even in subzero weather when moving.
Aftermarket stats tend to stay completely closed, then snap open rather suddenly at 195 or higher, causing thermal shock to engine components, especially in very cold climates.
I've seen issues with aftermarket stats that open very late, brand new, a 195 stat may not even begin to crack open until 210 or 215. This isn't good. Then a sudden rapid infusion of cold water when it pops open occurs.
My '04s heater works fine, at temps in the low teens it's able to get quickly to and maintain a set temp. If you pick full hot, it'll always blow full temp and not regulate, unbearable to me. When the system regulates temp, which will blend in outside air, as needed, through the face vents if the temp gets to or above the set temp. That can be a bit shocking, I'll admit.
I've measured 170 coming out of the vents at max heat.
edit: found this:
Originally Posted By: ;774689
Aftermarket stats cause issues in Hondas and many other imports.
The guy on the Ody forum is incorrect. The stat is NOT fully open at 172 and his C to F conversion is a bit faulty. If his stat was fully open at 172 its no good.
The factory stat that Honda uses starts to open at 176 and is completely open at 194. Your factory stat could be opening early. You'll never see this on the gauge, as a "normal" reading is 140~220. If you have a scan tool, watching the ect is a good way to know if you have any bleed thru the stat, it should come rather quickly to temp, maybe 5 minutes max even in subzero weather when moving.
Aftermarket stats tend to stay completely closed, then snap open rather suddenly at 195 or higher, causing thermal shock to engine components, especially in very cold climates.
I've seen issues with aftermarket stats that open very late, brand new, a 195 stat may not even begin to crack open until 210 or 215. This isn't good. Then a sudden rapid infusion of cold water when it pops open occurs.
My '04s heater works fine, at temps in the low teens it's able to get quickly to and maintain a set temp. If you pick full hot, it'll always blow full temp and not regulate, unbearable to me. When the system regulates temp, which will blend in outside air, as needed, through the face vents if the temp gets to or above the set temp. That can be a bit shocking, I'll admit.
I've measured 170 coming out of the vents at max heat.
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It's all computer controlled closed loop engine management.
Don't deviate with factory OE temperature (thermostat) rating.
Q.
Don't deviate with factory OE temperature (thermostat) rating.
Q.
I just added to my post above. ^^^^^^
Originally Posted By: bigt61
I figure the engineers knew what they were doing when they designed the engine.
Yup. You don't just go around swapping in a thermostat with different parameters than what your engine/cooling system was designed for. That's akin to swapping spark plugs with different heat range. You can do it, but you need to have a good reason for it, like some serious engine modifications. If your engine is stock, then leave your thermostat (and spark plugs) at the stock parameters.
I figure the engineers knew what they were doing when they designed the engine.
Yup. You don't just go around swapping in a thermostat with different parameters than what your engine/cooling system was designed for. That's akin to swapping spark plugs with different heat range. You can do it, but you need to have a good reason for it, like some serious engine modifications. If your engine is stock, then leave your thermostat (and spark plugs) at the stock parameters.
Originally Posted By: Avery4
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
The vehicle's cooling system is designed, in conjunction with the engine computer, to stabilize at a given temperature, typically 180 to 190F.
A 170F thermostat will allow the motor coolant to run higher than 170F; it's just the temp when additional cooling begins to operate.
Aluminum heads or head + block motors are more sensitive to higher temps than iron block + head models, so temperature control is somewhat more critical.
Performance motors can benefit from a higher temperature thermostat but cooling systems are also upgraded in conjunction.
Most modern vehicles have a temperature gauge that is equivalent to an "idiot light"; they "hang" at the ideal motor coolant temperature rather than indicate a linear temperature scale.
In other words they may read "normal" at, say 170 to 210F, and go straight to high above 210F. The "normal" and "high" indications are not actual temperature values. Automakers have found car buyers like gauges versus idiot lights, but the gauges operate as if they were idiot lights with really just three modes (too cool, normal, too hot).
A 170F thermostat will allow the motor coolant to run higher than 170F; it's just the temp when additional cooling begins to operate.
Aluminum heads or head + block motors are more sensitive to higher temps than iron block + head models, so temperature control is somewhat more critical.
Performance motors can benefit from a higher temperature thermostat but cooling systems are also upgraded in conjunction.
Most modern vehicles have a temperature gauge that is equivalent to an "idiot light"; they "hang" at the ideal motor coolant temperature rather than indicate a linear temperature scale.
In other words they may read "normal" at, say 170 to 210F, and go straight to high above 210F. The "normal" and "high" indications are not actual temperature values. Automakers have found car buyers like gauges versus idiot lights, but the gauges operate as if they were idiot lights with really just three modes (too cool, normal, too hot).
Manufacturers are kind of interested in getting good mileage with their cars and passing various smog tests.
Stick with OEM when it comes to stuff like this and trust that the engineers got it right. It's no big deal to admit that they know more than we do about how their engines work.
Stick with OEM when it comes to stuff like this and trust that the engineers got it right. It's no big deal to admit that they know more than we do about how their engines work.
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I would run the 195...
Better MPG....
I changed my 180 out for a 192.
Gained 4-6 MPG...
Car will turn fan on around 212, with 15 PSI radiator pressure.
Warning light at 220, begin melting at 230...
Better MPG....
I changed my 180 out for a 192.
Gained 4-6 MPG...
Car will turn fan on around 212, with 15 PSI radiator pressure.
Warning light at 220, begin melting at 230...
Originally Posted By: Quattro Pete
Originally Posted By: Avery4
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
This, I have told my son virtually the same thing except about cold air intakes.
Originally Posted By: Avery4
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
This, I have told my son virtually the same thing except about cold air intakes.
Originally Posted By: Quattro Pete
Originally Posted By: Avery4
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
Originally Posted By: Avery4
No mpg increase from higher temp?
If it was this easy and still safe for the engine, don't you think Honda would have given you a higher temp thermostat from the factory to improve their MPG claims?
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
The best course of action is to replace the thermostat after several years with the exact same part number. They get lazy after awhile and it should be done after several years and/or you suspect a cooling system issue.
Originally Posted By: kschachn
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
Not sure I understood the point you were trying to make.
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
Not sure I understood the point you were trying to make.
Originally Posted By: Quattro Pete
Originally Posted By: kschachn
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
Not sure I understood the point you were trying to make.
I was being sarcastic, I meant that Honda is constantly chasing tiny MPG improvements and if by simply changing the thermostat set point to gain a single-digit increase they would do so.
Originally Posted By: kschachn
You don't think Honda is wasting/throwing away/stopped looking for fractional MPG increases?
Not sure I understood the point you were trying to make.
I was being sarcastic, I meant that Honda is constantly chasing tiny MPG improvements and if by simply changing the thermostat set point to gain a single-digit increase they would do so.
gotcha. brain dead today.
In the Saturn world the accepted good thermostat to run is a 195 and most S series came with a 185 from the factory. I have been running a 195 in my S series since 2007 and have been happy with the heat in the winter, and the MPG all around (mainly in the summer)
I cannot say for Honda because I've never changed one but I can't see why it would be much different.
I cannot say for Honda because I've never changed one but I can't see why it would be much different.
Where the thermostat sits in the engine along with all the other design compromises leads to the final, happy combustion chamber temp. So a honda with a 170' stat might run warmer at the water jacket/ piston crown than a toyota with a 185' stat.
Theymay have engineered in some biases and fudge factors that work themselves out.
Though it's your car, as long as the fan isn't running all the time, it'll be "happy" with that warmer stat. Go for it and report back. I'd be particularly interested in datalogging knock retard.
They
Though it's your car, as long as the fan isn't running all the time, it'll be "happy" with that warmer stat. Go for it and report back. I'd be particularly interested in datalogging knock retard.
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