XLR8VRL

I posted before about losing 5 mpg with the 180* t-stat. I have been putting the stock tune in and out with the Diablo but no diff in mileage. So...today i put the stock t-stat back in. When the cooler stat was in I never saw below 194* on the Diablo, even up north last week in 20* weather. Now Im back in Fla (not hot but not too cold either) with the stock stat and she was running 188 even dipping down to 186. It was plenty warmed up and after a good WOT blast it went up to 190 but as soon as I let off it cooled back down to 188. Im wondering if i got a bad T-stat or if the stock one runs that cool - why change it. The stock piece seems like a better quality too. What do you guys think??? Well now we will see if the mileage improves. Ill keep ya posted.

XLR8VRL

any input guys

jimmyblue

iTrader: (11)

Sounds like the "180" stat was bogus. My
stocker ran around 194F pretty tight. Can't
see how either makes a 5MPG difference.

XLR8VRL

I dont either but it has deff lost mileage bigtime ive eliminated everything else-thats why i put the stocker back in today we shall see

Spooln

I have a 98 TA, it has a 180* stat in it from the factory. I can only go buy what my guage reads. I live here in ga near the sc border. I had been averaging about 22-23mph city driving in 70-90*temp. Now we went on a road trip to the Darlington in SC and the temp was in the high to low 30s. With road driving and far colder weather i only averaged 24mph with the car running in the colder temp. These aluminum engines must really disipate heat a lot better then the iron blocks. I think these LS-1s run better with the higher temp for gas mileage.

Z-Rated

Are you sure it opened? Stick that thermo in some water on the stove and put a thermometer in the water and watch it to see when or if it opens. 5 mpg? i dont know about that.....

XLR8VRL

I consistently got 30mpg highway and low 20`s around town - depending on how hard i hammer it. I put a custom predator tune and the 180 t-stat in at the same time. Highway dropped to 22-25 and around town down to a dismal 12-15 (#`s id expect from my old carbed stroker). Of course my first thought was the Predator tune - but ive been going back and forth with the stock and modified tune and no diff . So its got to be the stat - unless something else has gone wrong. I had an 01 WS6 that chewed up the axles at the c-clips and allowed the axles to "lean" in and out against the brakes. The FIRST thing I noticed was the loss of MPG so ...Ive already checked that out. Ive only got about 25 miles on it since the stock t-stat went back in - Im anxious to see if there is a diff too- I cant believe that 6* could make such a diff either.

Got Me SOM

iTrader: (2)

I dont think the t stat is your problem for losing gas mileage, I suspect its your predator tune, ie too rich.

XLR8VRL

Thats what i thought too but.. that was the 1st thing i did, put the factory tune back in. Dad seems to think that the fuel is reformulated in winter and gives you crappy mileage. For what its worth i have been trying diff brands of fuel - all quality brands of course - shell has an add campaign about being reformulated for better mileage well its seems to be the worst of them for mileage just my.02

WS6 RULES

I also have 02 WS6. I just leave in the stock 180. Put in Pred tune and if anything milage went up by 1 or 2 mpg. I drive half freeway and half city streets and average 21 mpg. But I also put my foot in it at least a couple of times a day. I lowered fan settings 5 degrees all the way around and bumped up the timing a bit.

blk~2000~Z28

What was the factory thermostat for '02 WS6's? If it was a 180* then why did you replace it with an aftermarket 180*? Why not put in a 160*?

The high temp factory thermostats are usually in place for mainly emmisions and fuel mileage. Changing to one lower than factory would most likely result in different fuel consumption characteristics but your case would be odd if 180* was your stock thermo.

XLR8VRL

Im not sure what the stock stat is rated at but it is stamped with "100* c" that is 212 if i remember my conversions correctly. However it is running COOLER than the hypertech 180* t-stat. Maybe Im not thinking correctly but doesnt efficiency = power, if its getting better mileage then it must be making more power --- right???

WS6FirebirdTA00

iTrader: (33)

in the owners manual it says my 2000 has a 180 stock, my friends 00 SS runs 186 completely stock. i have a 160 for detonating reasons and i did see a loss in gas mileage right after i did it. im guessing the colder engine temps are letting the gas come in more dense using more gas. thats my only thought....but i did lose MPG's after doing this i get about 14-16 in the city now and before, in the summer and 15 deg warmer engine temps i was getting 17-18...sounds weird but i believe this is a problem for shitty gas mileage....however it will help the car run stronger i think so ill give up the fuel mileage