160 degree thermo
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Pro
Joined: Jan 2000
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From: Salisbury MD.
160 degree thermo
I installed a 160 DEGREE THERMO in my ls3 and lost 4 mpg on a 90 mile run one way that I drive twice a week. Any thoughts on what may have caused the drop in mpg. The only thing that comes to mind is that the motor is not running hot enough to perform as before.
Thanks, C5-JIM
Thanks, C5-JIM
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Joined: Jan 2000
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From: Salisbury MD.
Team Owner
Joined: Feb 2001
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From: Short Hills, NJ
There is; fuel economy and emissions (both truly valid reasons to leave it in there of course...if going as fast as possible is of no concern to the owner that is).
I suppose that the Goodyear runflat tires and relatively soft rubber bushings that the car comes with are also the absolute best choice for all potential owner's needs/desires as well?
Sometimes yes, but not all of the time.
There's certainly nothing wrong with leaving a car bone stock but please don't ever assume that the factory put all of the absolute best performance parts (or programming) possible in the car when they built it either, there are always compromises and concessions made for various reasons. This is why the aftermarket world is so popular.
I suppose that the Goodyear runflat tires and relatively soft rubber bushings that the car comes with are also the absolute best choice for all potential owner's needs/desires as well?
Sometimes yes, but not all of the time.
There's certainly nothing wrong with leaving a car bone stock but please don't ever assume that the factory put all of the absolute best performance parts (or programming) possible in the car when they built it either, there are always compromises and concessions made for various reasons. This is why the aftermarket world is so popular.
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From: Arizona
Drifting
Joined: Oct 2006
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From: Phoenix AZ
St. Jude Donor '09-'10-'11
160 Thermostat
None of this is mentioned in depth above, but the purpose of installing a 160 stat is to make the engine run cooler. The less heat generated by an engine, the less friction and wear is generated. Just installing a 160 stat without programming it properly in the ECM will do nothing to cool the engine. A thorough way to accomplish this install is to program the ECM accordingly so that it "recognizes" the new temp setting and activates the cooling fan/fans in progressive stages. Without this the 160 stat is opening but the fans are not activated until 186.8 degrees (the value of the original stat) hence, NO real cooling effect. I have a 160 stat in my 06 Z51 Coupe and it runs 30 degrees cooler now--approx. 178-182 degrees, than prior to the change. This reprogramming IS necessary in order to take full advantage of the lower temp stat.
Le Mans Master
Joined: Aug 2008
Posts: 5,578
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From: Austin TX
Thermal efficiency. The colder the engine, the more it acts like a heat sink sapping combustion energy from the combustion chamber.
Since these engines are very high compression and run on pump fuel, the "racers" add the 160 thermo in an attempt to add a little more timing to get some extra hp at full throttle. It's a balancing act, the thermal efficiency is down, but adding timing recoups it and possibly adds a few hp.
Since these engines are very high compression and run on pump fuel, the "racers" add the 160 thermo in an attempt to add a little more timing to get some extra hp at full throttle. It's a balancing act, the thermal efficiency is down, but adding timing recoups it and possibly adds a few hp.
Burning Brakes
Joined: May 2006
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From: foley al
Thermal efficiency. The colder the engine, the more it acts like a heat sink sapping combustion energy from the combustion chamber.
Since these engines are very high compression and run on pump fuel, the "racers" add the 160 thermo in an attempt to add a little more timing to get some extra hp at full throttle. It's a balancing act, the thermal efficiency is down, but adding timing recoups it and possibly adds a few hp.
Since these engines are very high compression and run on pump fuel, the "racers" add the 160 thermo in an attempt to add a little more timing to get some extra hp at full throttle. It's a balancing act, the thermal efficiency is down, but adding timing recoups it and possibly adds a few hp.
Safety Car
Joined: May 2000
Posts: 4,823
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From: Albuquerque NM
true, also when the computer see's a cooler engine coolant temp it runs richer.winter time might affect mpg more adversly with a 160 thermostat.never seen much change in GM cars, run several with a 160 t),had a 1992 5.0 mustang, running in 30 degree temps it lost 4 mpg with a 160 thermostat,mileage came back with an 180 degree one(stock was a 192 one) a cooler running engine allows more timing advance and less spark retard
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From: Salisbury MD.
160 thermo
[QUOTE=6Speeder;1571470762]I doubt that the thermostat caused you to lose 4 MPG. I saw no change in MPG with a 160 in both my C5 and my current C6 Z06. Something else caused the change.[/QUOTE
You have 2 entirely different motors than what I have. Maybe my engine does not like any changes that affect the computer. The motor is an LS3 with 6000 mi and the ONLY change to the car is the 160 and window tint with the gas being bought at the same station each time. I monitor my car with the fillups and the onboard computer.
I guess maybe the window tint cost a loss of milage.
C5-JIM
You have 2 entirely different motors than what I have. Maybe my engine does not like any changes that affect the computer. The motor is an LS3 with 6000 mi and the ONLY change to the car is the 160 and window tint with the gas being bought at the same station each time. I monitor my car with the fillups and the onboard computer.
I guess maybe the window tint cost a loss of milage.
C5-JIM
Safety Car
Joined: Sep 2007
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I installed a 160 t-stat in my 2009 LS3 several months ago and have seen no measurable difference in MPG numbers. I'm still seeing 18-ish mpg around town. 29-30mpg on the interstate at 75mph and 31-32 mpg on my "mileage champ" flat for 110 miles at 55mph road.
Just finished a headers, ported manifold and TB upgrade which will probably change those numbers but haven't had a chance to measure the impact yet.
Perhaps my results are different because I live in Florida where it is hotter?
Just finished a headers, ported manifold and TB upgrade which will probably change those numbers but haven't had a chance to measure the impact yet.
Perhaps my results are different because I live in Florida where it is hotter?
Last edited by Motorhead-47; Sep 12, 2009 at 05:10 PM.
Burning Brakes
Joined: May 2006
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From: foley al
14.7 a/f in the cooler winter temps uses more fuel to acheive 14.7 than in the summer, as denser cooler air takes more fuel to make the same ratio, true? it also makes more power. just wondering..
Burning Brakes
Joined: Jul 2008
Posts: 923
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From: Green Bay Wisconsin
The less heat generated by an engine, the less friction and wear is generated.
Hello all,
Actually the above statement is incorrect. With a cooler thermostat engine wear in accelerated.
Why? Because GM adjusted the internal tolerances of the engine to full operating temperatures (expansion and contraction of metals). If the engine never gets to the operating temperature that GM designed it to reach, internal engine wear is accelerated.
Engine should also make more power and get slightly worse gas mileage.
It's a give and take, with every action you get an equal and opposite reaction.
Douglas in Green Bay
Hello all,
Actually the above statement is incorrect. With a cooler thermostat engine wear in accelerated.
Why? Because GM adjusted the internal tolerances of the engine to full operating temperatures (expansion and contraction of metals). If the engine never gets to the operating temperature that GM designed it to reach, internal engine wear is accelerated.
Engine should also make more power and get slightly worse gas mileage.
It's a give and take, with every action you get an equal and opposite reaction.
Douglas in Green Bay
Team Owner
Joined: Feb 2001
Posts: 27,253
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From: Short Hills, NJ
With a cooler thermostat engine wear in accelerated.
Why? Because GM adjusted the internal tolerances of the engine to full operating temperatures (expansion and contraction of metals). If the engine never gets to the operating temperature that GM designed it to reach, internal engine wear is accelerated.
Why? Because GM adjusted the internal tolerances of the engine to full operating temperatures (expansion and contraction of metals). If the engine never gets to the operating temperature that GM designed it to reach, internal engine wear is accelerated.
...but please do tell me exactly how my motor, with it's 160 degree thermostat installed, isn't reaching the operating temperatures that GM designed it to reach? Not sure about anyone else but I always warm my cars up properly/completely before driving them aggressively regardless of what thermostat is in them.
And please define operating temperature? Certainly not an easy task considering that a Corvette's operating temperature will be entirely different at legal highway speeds during January in Vermont than it will be in traffic during July in Southern Arizona.
And now if that range is acceptable with a stock t-stat then why isn't acceptable with an aftermarket one?
I've seen stock LSx motors with stock t-stats reach coolant (and oil) temps in the 240 degree range in stop and go traffic during hot summer days with the AC on, that's pretty damn hot.
Race Director
Joined: Oct 1999
Posts: 13,298
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From: Somers NY
Mark
I'm with you 100% someone mentioned above about how the fan wont come on .. etc.. My fan NEVER comes on if I'm driving on the GSP or I95 at 65-75 mph and even with my 160 T Stat my engine temp is 175 - 190 deg... I have had my car out in 10 deg weather in Feb. and the engine still never got to 160 deg...so I'm thinking the T Stat opens at 160 and never closes again...
If my engine gets over 192 the fan goes on Hi... Julio set when you were there...
I get about 26-28 mpg on the highway at 70 mph... 18- around town...
I'm with you 100% someone mentioned above about how the fan wont come on .. etc.. My fan NEVER comes on if I'm driving on the GSP or I95 at 65-75 mph and even with my 160 T Stat my engine temp is 175 - 190 deg... I have had my car out in 10 deg weather in Feb. and the engine still never got to 160 deg...so I'm thinking the T Stat opens at 160 and never closes again...
If my engine gets over 192 the fan goes on Hi... Julio set when you were there...
I get about 26-28 mpg on the highway at 70 mph... 18- around town...
Melting Slicks
Joined: Oct 2007
Posts: 2,702
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From: Northwestern Connecticut
St. Jude Donor '10 thru '26
See if your oil consumption increases too. I noticed my c5 dropped a couple mpg with a 180 stat and reprogramming the fans. Then it hit me, on my 68 camaro with a aluminum block motor, ring seal sucks at lower temps, I increased that car to a 195 stat and ring seal is a lot better. I've cylinder leaked it and it went from 10% leakage to 5% in a ~30 degree temp dif. I recall a thread in the c5 forum reporting similar problems with ring seal on the lower temp... helps the intake air temp, but hurts ring seal.
For ref, the only reason I dropped my c5's thermostat was to try and help on-track heat build, start at 180 instead of 210 so I get more laps before the water and oil temps skyrocket! (I know bigger radiator and oil cooler!) -Dan
For ref, the only reason I dropped my c5's thermostat was to try and help on-track heat build, start at 180 instead of 210 so I get more laps before the water and oil temps skyrocket! (I know bigger radiator and oil cooler!) -Dan