bgray

iTrader: (2)

hey guys...hashing things out on the dyno today, and with my 99 5.3 with Dual flexalites on it, the temps got to 202 degree coolant temeparature....

Would it help if i bought a 160 thermostat? Mt tuner seems to think so, but i remeber someone saying these trucks like to run hot..is this any different

RandomHero

iTrader: (24)

it will help a bit but keep in mind you'll lose gas mileage. My truck runs at 198 with the stock fan and I get 20.5 mpg, just FYI.

03sierraslt

iTrader: (22)

I would consider that normal, mine runs at 192 on the highway. In traffic it will hit 200, this is when I have my fans set to come on. I rarely hear the fans kick on. It takes mine a while to get to 200 when sitting still.

budhayes3

iTrader: (19)

202* is normal with the factory thermo...I used to see 202-203* with the stock thermostat and factory clutch fan in the summer after beating on it.

truckmann

iTrader: (8)

I'm with them. 202 on the dyno isn't bad. Mine runs around 198 and I am happy.

gmforlife

iTrader: (2)

If you run a 160 stat it will actually run at around 170/180ish, the stock thermo is a 186, that's what it says on the actual thermostat, and obviously stock thermo's run at 200 or so. So technically a 160 stat isn't 160, FYI

bgray

iTrader: (2)

okay..so really..this isnt anything outta the norm then. I'll leav eit be and save my mpg

99LoweredSierra

iTrader: (7)

You shouldnt lose mileage if its tuned for it. I got mine tuned for it!

RandomHero

iTrader: (24)

I've heard differently. I have no personal experience but I've heard from at least 5 people who have the 160* stat and tuned for it and they lost a full 1 mpg.

gmforlife

iTrader: (2)

Well with the lower engine temp you can add like 1 more degree of timing, but i don't know about losing 1mpg, might or might not. I think if it were me i wouldn't give a crap cause i get shitty mileage anyway, what's 1mpg less to me? Nothing!!!!!!!!!