tobijohn

I know all about the positives of switching to a 160 T-stat and reprogramming the fans but are there any negatives? I'm in south Florida so I'm not concerned about hard starting in sub-zero weather however, I did read on one of the many threads regarding cooling that on CF member was going back to a 180 T-stat because it was costing him 2-3 mpg. He didn't elaborate on the cause/effect of this and I can't recall the exact thread. Why would that be and are there any other reasons one might NOT want to go to the lower temp T-stat?
Thanks

Alex D

I am running the same stat.......In your climate I don't believe there are any drawbacks to a colder stat......i don't drive my car in the winter...if i would, i would not run a 160F stat

A lot sources state that the optimum engine temp is around 200 to 210 F ... also motor oil should be running right at that temperature to burn of condensates......

tobijohn

Alex D wrote:
"In your climate I don't believe there are any drawbacks to a colder stat."

Thanks Alex. Have you heard anything about this purported 2-3 mpg loss?

Alex D

I can't substantiate that, but it could be true.......mine gets around 20 mpg...maybe up to 22 , but not better......more important than all of that: i really don't care as long as I don't get much worse than 20 mpg......

vader86

No reason not to in S FL. You dont have to worry about cold weather down there.

I lost no average mpg with the 160. Its the cold weather combined with the 160 that gets your gas mileage down, the car stays in open loop longer and the ECM richens the mixture.

MTVette

I've been running a 160* thermostat for the last 18 months, including all last winter here in New England. Since my vette is my only car, I drove it all winter. I use an Ed Wright Fastchip to set the fans at 182 (on) and 173 (off).

Overall, this setup has worked very well. One disadvantage of using the Fastchip is that the car now requires high octane gas (92+), whereas the stock setup can run quite well - so long as I'm not racing - with regular 87 octane gas. The biggest problem I noted during the winter was that it took a long time to heat up the passenger compartment. At an outside temperature of nearly zero degrees F, the interior was never confortable. Next fall I intend to swap back my 180* thermostat and take out the Fastchip. Probably I'll use regular gas again from time to time.

Alex D

You can run the fastchip with premium fuel in the winter on a 180F thermostat..no problem...it is cool enought o pervent detonation.....once it gets warm though, you need to go back...

TheCorvetteKid

I went from the stock 190 tstat to a 160 tstat, then pulled it in favour of a 180 tstat. And to be honest, I wish I had left the 160 tstat. The only difference I've noticed between the 180 and the stock 190 is on the highway - my car would sit at about 195deg with the stock tstat, and about 186 with the 180 tstat). In city driving they are virtually the same. The 160 tstat would give me about the same temps on the highway as the 180 tstat, but the difference came in city driving - the temps where ALOT lower. And when they did climb (say in bumper-to-bumper traffic), they dropped very quickly once the car got moving again. And I'm in Ontario Canada. If I were in your shoes, I would DEFINITELY go with a 160 tstat.

P.S. I should mention, I was (and still am) running a stock chip

Storz

I have a 160 stat in mine, and used it last winter, however for this winter I am putting a hotter one in, need heat :eek:

black bart

No draw back to the 160 but unless you change the fan on setting it will run about the same tempature because when the stat opens temp will keep climbing until the fan comes on. To make it run cooler change the stat and reprogram the fan on temp. One of the best mods that I did to my car was to install a grill now it don't depend on the fans and on the open road the fans don't come on and it runs about 170 on the road. That is a little cool for most but I try to run cool to help control detonation at full boost my C/R is 21-1 requires very good fuel. :chevy

okinawa86vette

The reason for the mpg loss was probably because the computer was never getting out of the open loop program and into the closed loop(normal op mode). I've heard of a lot of people running a 170 degree because it's the coldest t-stat that will make sure it'll get out of warm up mode(open loop) with a stock comp chip/program. I run a 180, btw, but I knew I was going to Colorado.

Chris

Alex D

okinawa..that is not correct...going from open to clsed loop happens already at 120F and is also time controlled, not only temp.....any stat on the amrket will allow the car to go into closed loop....if you would really drive around in open loop all the time, you mileage would be dropping a lot more significantly

Alex D

I don't have the HPP fan settings change in my car.....you don't need it....if you get into traffic and the temp starts rising, just turn the a/c on and the fans will come on permanenetly below 40 mph and keep your car cool.....mine runs only 180 to 185 F even in 90F weather with the a/c running.

tobijohn

Alex D wrote:
" don't have the HPP fan settings change in my car.....you don't need it....if you get into traffic and the temp starts rising, just turn the a/c on and the fans will come on permanenetly below 40 mph and keep your car cool.....mine runs only 180 to 185 F even in 90F weather with the a/c running."

Alex, during a south Florida summer, believe me, the A/C IS on. Regardless, the lowest I run is 205 and that's on the open highway. In stop and go traffic, I'm up at 235-240 with the A/C on which I do NOT like at all. THe car goes into the dealer on Monday for some minor unrelated work covered under the extended warranty. I'm going to have them do a full flush to see if that makes a difference. If not, then back to have the radiator pulled, the fins cleaned and straightened and perhaps a boil as long as it's out. Too many people on this forum with 96 LT-1s seem to have no problem keeping their coolant under 200 all the time so there's really no excuse for me not to, either. I'm familiar with all the talk about these engines normally running hot yada-yada but honestly, is 240 under these conditions within the GM spec?


[Modified by tobijohn, 3:27 PM 7/6/2003]

Lone Ranger

:lurk:

Southern Comfort

From what I understand about the cooling system the thermostat only allows water to flow when it reaches the temp allowing the radiator to send cooler water to the block where the thermostat closes back up and the radiator cools that batch of water and the engine heats the other. That cycle is repeated over and over.

As hot as a vette runs in the summer, once it reaches 160 probably stays open all the time so eventually the heat from the engine catches up with the efficiencey of the radiator. how long that takes and what temp it settles on depends on outside air and road temps and the proper operation of the fans.

I summary, in the summer it dosent mean squat. In the winter it probably works as advertised.
:yesnod:

Lone Ranger

The Hypertech 160 I am using flows coolant better when open than my stock 180 did. It could be my stock 180 was getting bad and that is why but there is no other explanation for the fact that with the 160 I run 180's on the highway and used to run 190's w/ the stock 180 on the highway. I'm not currently using fan programming, so the tstat is the only variable in the equation that has changed.