160F vs 195F thermostat

[CCI]

1993 5.7 TBI Chevy 2500 a little over 202K miles. Looking at the temperature gauge it seems like there is probably a 160 degree T-stat installed.
Looking at the stock specs it calls for a 195 as OEM.
What are the possible advantages or disadvantages of each?

 

[ripcord]

I'm general, a cold thermostat will increase cylinder wear, reduce the effectiveness of the cabin heater and reduce gas mileage slightly.

Edit: I remember back in the day my Chevy friend talking about a cooler rated thermostat to reduce pinging in his Chevy truck. Don't know if that's effective or not.

 

[OVERKILL]

I'm general, a cold thermostat will increase cylinder wear, reduce the effectiveness of the cabin heater and reduce gas mileage slightly.

Edit: I remember back in the day my Chevy friend talking about a cooler rated thermostat to reduce pinging in his Chevy truck. Don't know if that's effective or not.

This. A 160F stat is generally a poor choice for these reasons. Some engines start pulling timing at higher temperatures (like the EEC-IV Fords) so moving down to a 180 is a good balance, and what I always preferred in those applications. Without knowing your timing/temp map, I can't say the same benefit would extend to your application, it might be fine with the 195.

 

[eljefino]

You could also have a lazy 'stat, they do fail partially open.

Can meet in the middle with a 180.

Colder: Less pinging, "better" performance, more "surge" headroom if something's marginal in the system.
Warmer: Better MPG, better emissions, better engine wear, better oil wear (less gas and water vapor condensing in it.)

If you do in fact have a 160, you might have a problem the previous owner masked. Or he might have just been old-school. Give yourself time if you start messing with things.

 

[chainblu]

I'd make sure it's not a gauge problem before I start tinkering. That sensor could be 32 years old.

 

[Chris142]

I'd make sure it's not a gauge problem before I start tinkering. That sensor could be 32 years old.

Yes assuming the guage is correct put the correct thermostat in it.

 

[nascarnation]

Use your heat gun to double check the temps. The gauges on these get pretty iffy in their old age.

 

[oil pan 4]

1993 5.7 TBI Chevy 2500 a little over 202K miles. Looking at the temperature gauge it seems like there is probably a 160 degree T-stat installed.
Looking at the stock specs it calls for a 195 as OEM.
What are the possible advantages or disadvantages of each?

The 160 has all the disadvantages.
No advantages.

 

[Exhaustgases]

If its a computer controlled engine the coolant temp has a certain spec for everything to work correctly. If the temp is low the computer thinks the engine is cold and makes the air/fuel rich for warm up, and likely adjusts the advance as well. Nothing gained running it at a low temp.

 

[CCI]

Ample reason to swap it out for OEM 195 here. Thank you all.

I went to change it today and the two bolts for the gooseneck are over-tightened or rusted in place or both. Having broken a few 3/8" bolts over the years, these are definitely candidates. The half-inch drive ratchet says these are going to break before they turn. The electric impact and the hand impact with the 2 lb. hammer did nothing.

Applied some ATF/mineral oil mix and will continue to do so for a week of so and then try again.

Meanwhile we'll see what the NCIR thermometer says.

 

[RDY4WAR]

I keep a mix of 75/25 acetone/ATF in a spray bottle for that purpose.

As has been stated, a 160°F stat is undesirable for anything other than (maybe) a drag car. The lower temp means less cylinder and intake heat to vaporize the fuel which means more fuel wash of the cylinder walls, reduced air/fuel homogenization, and increased piston and chamber deposits. It also reduces the effectiveness of ZDDP which relies on heat for reactivity. The trade-off is a little better knock resistance and a hair more power (less than you'll ever feel with the butt dyno). To make matters worse, many EFI engines are still in warmup mode at 160°F, and there's been quite a few people see a substantial drop in fuel economy due to the engine never getting out of warmup mode, still dumping fuel.

The engine should appreciate the 195°F stat.