hotter thermostat for more mpg

[ex-x-fire]

Has anyone installed a hotter thermostat for increased mpg? I had a scanner on my 2010 yaris for the 1st time, I noticed the temp never got hotter then 185. It make sense b/c it has a 184 stat in it & it was cool out that day (low 50s).
I've had some experience on GMs with hotter t stats & improved mpg. It usually adds a couple highway mpgs esp. on colder days. The TDI guys have had great luck with them.

[bronsin]

I tried a block heater and it didnt improve mpg enough to make it worth the $$ and trouble.

I doubt very much you would notice the increased mpg (if any) from a hotter thermostat. And I can think of problems like over heating the engine in stop and go traffic in summer or burning out the fan sooner or something similiar.

[ex-x-fire]

Why wouldn't I see an improvement? Esp. if the engine is running right at the t stats rating, the fan shouldn't kick on till 205. The coolant temp sensor that tells the computer the temp has a huge impact on fueling the engine.
I had a gm truck that I ran a 180, 195, & 205 stats. I lost mileage with the 180 (-2-3mpg) & gained some with the 205 stat over the stock 195.

[woops]

If you live in a cold area that makes sense otherwise just kill this thought of yours :p

[bronsin]

Why wouldn't I see an improvement? Esp. if the engine is running right at the t stats rating, the fan shouldn't kick on till 205. The coolant temp sensor that tells the computer the temp has a huge impact on fueling the engine.
I had a gm truck that I ran a 180, 195, & 205 stats. I lost mileage with the 180 (-2-3mpg) & gained some with the 205 stat over the stock 195.

I guess I really dont know if it would make much of a difference. My gut just tells me it wouldnt and that it could cause problems you would rather not have.

But I might be wrong.

Try it and see. You can always go back to regular.

[WeeYari]

You've touted personal and known experiences with other manufacturers. T-stats are cheap enough to experiment. Do it, be the first here and blaze a trail.

[ex-x-fire]

Yeah, I've been looking at different ones. The yaris takes one with a 56 mm base, I'm having trouble finding a hotter rated one. I might have to combine 2 to make one.

[why?]

Or you could block off some of the front vents and get the same effect with a little better aerodynamics to boot.