Increasing engine operating temp to increase MPG

[rmay635703]

On some cars (like mine) the head gasket blows faster and more readily above 200F water temps.

[Piotrsko]

Above is best demonstration about hot spots. Leads me to believe the head is stress relieving itself to something other than flat.

[Big Dave]

A 203 degree stat improved my MPG by about 0.5 MPG.

[redpoint5]

0.5 MPG in what vehicle, and what was the stat before, and what % improvement does that represent, and how did you control for other variables in measuring the improvement?

Anecdotes are nearly worthless just by the nature of them being anecdotes, but they are made even more useless when the details are omitted.

I had a disc burst and impinge on the spinal nerve at L5-S1 that left me in excruciating pain. Desperate to do anything to relieve the pain, I visited a chiropractor. He told me the bad news is that my back is messed up (duh), but the good news is I should see a great reduction in pain if I saw him 42 times in the course of 2 months. Rather than do that, I did nothing and my inflammation/pain subsided in 2 months. Had I made the 42 visits, I'd likely attribute my excellent results to the therapy when in fact my body recovered naturally.

My point is that correlation does not equal causation, especially when practically no variables are controlled for that could potentially confound the conclusion.

[Big Dave]

Jeez dude! I did that mod nearly 18 years ago.

If memory serves it went from 19.3 to 19.8 MPG. It was my first ecomod.

I think the old stat was 190 degrees. The old school bus motors are designed to run fairly hot.


I don't think there are any hotter stats available for that engine.

[MeteorGray]

I strive for good MPGs as much as reasonable, but I won't run the water or oil any hotter than the manufacturer thinks it should go. The longevity of an engine trumps eking another MPG or two out of a gallon of gas.

Since I live in the South, I'm always watching for excessive oil and water temperatures during summer months and look for ways to keep them in check. In fact, I even put louvers in my Mazda3's hood to manage excessive engine bay temperatures which kill batteries and other things which can be degraded by excessive temperatures.

IOW, fuel economy is important to me, but it doesn't trump everything.

[oldtamiyaphile]

Since this is on the topic of thermostats, what do we think of high flow 'stats?

https://www.stewartcomponents.com/in...ormation_id=11

[Taylor95]

Originally Posted by oldtamiyaphile

Since this is on the topic of thermostats, what do we think of high flow 'stats?

https://www.stewartcomponents.com/in...ormation_id=11

I think the perfect combination would be a high temp high flow stat, but they don't offer that for my vehicle. The thermostat only regulates the minimum coolant temperature, so having a high flow high temp stat would help keep the engine coolant in a more narrow range. I'm sure it would be particularly helpful in hot climates.