First full tank after thermostat changed...

[SRRAE]

I decided to change the thermostat as according to several apps using the ODBII the temperature never reached over 75ºC even driving 3000rpm for several miles. The standard thermostat should open at 82ºC and I suspect the car was on cold running all the time. Now it takes about 1-3 miles for the dash to read 90ºC, where previously it never got close. According to the ODBII reading it stays around 90-95ºC.

Previously with a mixed month or work and the odd long drive down the motorway, I'd be lucky to get 450 miles to a tank. This equates to 38-41 MPG when calculated using brim to brim method.

Although this month hasn't been a completely typical month, I've currenlty done 560 miles and the trip is saying I have 50 miles left and this is with a hot month and I've had the aircon on every time. Even if I dont get another 50 miles from whats left in the tank, Im still getting 100miles more per tank at least.

All in all it seems a worth while endevor for me.

 

[Diesel bob]

What engine do you have and how easy or how much was the thermostat change? My fuel economy is terrible and my car obd temp will not go above 80C

 

[SeanTFSI]

My fuel economy is terrible but sadly my car does read 90C without fail so no easy savings there XD

 

[Jon B]

Sounds like a good improvement. Not knowing how you drive, in the current weather I am achieving close to 700 miles per tank from my 2.0 TDIe 136bhp.

 

[SeanTFSI]

I'm not hypermiling but driving a lot more sensibly, my fuel gauge says 550 miles or so and I get about 350.

 

[666markyboy]

To the original poster, those figures sound much better and are on a par with mine (2.0 TDi 170), I do a mainly motorway commute and a bit of pottering round at the weekends and can get around 600 miles out of a tank , I doo drive a bit miss daisy though on the motorway in the mornings never really going above 60 and the 70 on the way home I have noticed though if you push these engines they are not anywhere near as economical as the old 1.9 PD engines, much more refined though, Glad you got it sorted