aaks38

Im curious those of you whom are running the 160 degree thermostat, I have noticed after 6 months driving with it, my mpg has went down slightly (maybe 1mpg) which I don't care for much. However what im curious is that with the delayed warm up, does this increase fuel dilution into the oil? I guess what im wondering is that if you do run the 160 thermostat, is it necessary to reduce the oil change interval and/or possibly increase the oil weight due to fuel dilution?

Thanks

ADias

I am not in favor of lower temp thermostats.

HenryPcar

Subscribed

Wayne Smith

I've read pros and cons on low temp thermostats. I still believe they are a bandaid for an underperforming cooling system. I'd prefer a faster warm up followed by actual operating temperature regulation. A third radiator makes more sense.

As for your question, a return volley ... How far do you drive generally? What temp does the oil achieve? Are you steaming the water out of your oil?

Petza914

You drive a high-performance sports car and are worried about 1 MPG? You don't think the mileage difference is because the past 6 months were the hottest time of the year where air is less dense and your engine has more thermodynamic losses because of the ambient temperature.

To answer your questions, no the LTT doesn't effect gas mileage, nor does it have anything to do with fuel dilution in the oil. Leaving your car sitting still idling during the initial start enrichment phase does. There are probably 25 threads discussing the LTT if you search for them.

LexVan

You are losing a small amount of MPGs because the car is running cooler in the early stages of driving.

aaks38

I think you guys misread my post, as I don't care for the mpg loss and know this is due to the engine spending more time in open loop trying to warm up with a rich fuel mixture before it enters a closed loop profile. What im curious about is the side effects of fuel dilution and cylinder wall washing.

rtl5009

bhvrdr

Its a reasonable question but i doubt anyone has done truly controlled oil analysis on multiple units pre and post 160 thermostat change.

mike

LexVan

What makes you think you even have fuel dilution? Only way to know is to conduct a flashpoint analysis on your oil.

I doubt you have a low flashpoint and fuel dilution. Idling and lots of short trips are the main cause, not colder starts.

996AE

LN and FlatSix recommend Low T

These firms know a lot about our cars.

That's enough for most.

Petza914

I have by accident. My wife's car had the regular 180 degree thermostat when we bought it. I didn't change to the LTT until the water pump failed about 20,000 miles later, so my UOA from Blackstone, which I do on every oil change, were done with the 180 degree thermostat for the first 4 and the LTT for the past 6. None of the samples had any report of fuel dilution in them. I can probably post the reports tomorrow.

bhvrdr

haha thats awesome man. Good information to have come by.

mike

floatingkiwi

The LTT doesn't have a slower warm up people, it circulates the water in the block just like the factory thermo until it gets to its opening temp, when it lets it circulate through the rest of the system - just like the factory one, albeit at a slightly lower temp. They both still warm up to 160 deg at the same rate!

Petza914

Correct, but they don't both warm up to 180 degrees at the same rate or 190 degrees at the same rate. At 180, the LTT is fully open and it took a while to get there since it started opening at 160 - this is the attribute that might actually help to prevent bore scoring, whereas the 180 degree is just starting to open at that temperature and not fully open until 200 which has allowed the engine to warm to 180 at a much faster rate, and parts of the engine are hotter than that since coolant in the block is just starting to mix with the larger coolant supply at 180