Lower thermostats, really needed?

[JennaBear]

A common belief is that a cooler running engine will reduce intake air temperature. The reality is that outside of idle, there is very little heat transferred from the engine to the intake charge. The mass of air moving across the incredibly small surface area of the intake ports is too large and too fast to allow for any large temperature transferance.

As a vehicle sits out overnight, you may notice condensation on the windows, hood, etc from moisture in the air. That same moisture ends up in the crank case as well. An engine that does not reach the manufacturers operating temperature will not as easily boil off that condensation, especially if only short trips are taken.

Here is some info to further whet your palate: http://www.tuneruniversity.com/blog/2012/04/low-temp-thermostats-whats-the-advantage/

With a 160* thermostat, the average operating temperature of a GM engine is approximately 180*. With the OEM thermostat, it is around 199*. A few minutes on the dyno can quickly show temps above 210-220*, regardless of the thermostat. As long as intake air temperatures remain static, power output is static and sometimes even BETTER under the 210-220* range.

In short, keep your stock tstat.

 

[vatahoelt]

good info to know. another thing on our trucks not to waste our money on.

 

[Z-56 Hoe]

Thanks Jenn!

 

[SnowBuck]

EXCELLENT INFO!!!!
I always think cars run too hot. But then I work on 50's cars. LOL, people would take OUT the thermostat thinking it'll run really cool! LOL - RAN HOTTER!!! Water would flow too fast thru the radiator and it couldn’t dissipate the heat.

 

[JennaBear]

Yep, the tstat is a regulator, not a heating or cooling device.

Back I'm the old iron block days a lower tstat definitely had benefits.

Sent from an ice cream sammich.

 

[Wake]

Good info.

One other observation I've had over the years on older ODB controlled vehicles is that a cooler fan setting along with the stock thermostat keeps temps nice and steady.

I've always used the 180F thermostat but used a programmer to turn the cooling fans on at 172F. The fans turn on slightly before the engine reaches operating temp but I always keep a rock steady reading on the coolant temp. It keeps the temps from cycling between 200 and 240F in stop and go traffic.

 

[TahoeLimited]

Not Convinced...

I've owned several Buick Grand Nationals (5, actually), and one of the most popular initial mods is the 160 deg. t-stat. Maybe it depends on the engine, but I'm very confident that my GN had an easy 40 more hp when it just warmed up enough to give it some throttle. I always looked forward to that first blast when coolant temp was about 140 deg...it was a rocket. Fast forward 20 minutes later, and definitely a noticeable loss of hp. Okay, so some of it may be the intercooler heating up. But even after long periods of cruising, to allow the IC to cool down, it was never as fast as the first blast ~5 minutes after heading out.

I *just* bought an 00 Tahoe Limited 3 days ago, and think I can also detect a hair of the same phenomenon...seemed extra peppy at about 160 deg. on the temp gauge on it's way up to fully warmed up.

Aside from Buick Grand Nationals, which my confidence is high, one can argue back and forth all day. The real test isn't easy - several dyno runs with the same outside temp with higher and lower degree t-stats.

On a related note...I may need a new t-stat. I've noticed the temps hitting over 200 (close to 210 maybe) before the t-stat opens...don't like it.

 

[JennaBear]

Are you watching your temps through the computer or through your gauges? You are also talking NA vs FI and iron block vs aluminum.

Sent from a jelly bean.

 

[TahoeLimited]

Are you watching your temps through the computer or through your gauges? You are also talking NA vs FI and iron block vs aluminum.

Just looking on the gauge...if you're responding to my statement about the temp reading 210 before the t-stat opens.

Yes, I understand that they are different animals. What motor has got the aluminum block?

---------- Post added at 10:30 PM ---------- Previous post was at 10:28 PM ----------

And to clarify...it's hitting ~210 for just a moment until the t-stat opens for the first time after a cold start-up. Once it's open, temp is fairly steady probably about 180-190.

 

[JennaBear]

When the needle starts moving at 160*, it is actually 130*.

A properly tuned vehicle has no benefit from a colder temp stat. When not properly tuned, there is more ignition timing when it is colder, which yields more power.

Sent from a jelly bean.