I start my car in the morning and drive to school. School is about 4-5 miles through the heart of the city, so it takes about 20-25 minutes on a weekday at 7:30 AM. Car is usually not at operating temp until I am pulling into the parking lot, or just a few minutes away depending on traffic. Either way it is taking over 15 minutes of city driving to reach operating temp. I understand that having the heater running can cause the engine to take longer to heat up, but does this sound right?

I've been trying to figure out my crappy gas mileage - car gets 10MPG mixed highway/city. Strange as this may sound, it gets the same mileage if I granny it or if I floor it at every light. And i've tested that through SEVERAL tanks. 10mpg no matter what. Related?

 

Thermastat may be stuck open I would start there being a very cheap part.

 

What's the ambient temperature? What do you consider operating temperature?

Regarding the fuel mileage, there are many possibilities. Some ideas are the car is stuck in open loop mode, bad ignition (spark plugs, distributor cap, timing, distributor could be installed a gear off), etc.

 

in cool temps like 50-60 degrees, my car used to take about 5-10 min to heat near running temp.

hotter days it only took around 5.

cold days such as winter, it take 10.

now with my 170 degree thermo, it doesnt heat up much at all no matter how long u let it sit. haha

 

Did you have a 195 before?

What's the max temp it gets to driving around with the 170 and the old t-stat?

 

i had stock 195 before.. and it was near 200 degrees all the time. sittin in traffic it climb to 230-240 in the summer.

cold days it reach 200-220 as well if idling.

i was not having that. so i wired a manual switch and it helped some

now have the 170 Tstat and in the cool days of 60-70 degree weather, it would not go over the mark on the factory gauge which is between 220 and 110 or w/e the lowest one is. i'd say it barely reaches 170 degrees with the manual fan on the whole time, and hovers around that with the fans off.

in the cold days of 30-40, so far it does not get hot at all... and thats with both fans off. i'd say 120-140. its just over the bottom mark on the gauge. it took a long time of idling in traffic and running hard to get it to reach near 170ish.

 

is that too low? mine sits around 180-220 on a hot day (37'C or almost 100'F) and 160 any other day, with a gutted t/stat (constant flow) installing a 180 t/stat soon, Dual fans out of a wrecked jap car 1 on the factory wiring the other on a switch, on a normal day of 27'C with manual fan on it dose not get hot enough to turn the normal (auto) one on.

To reply to the main thread my car takes about 10-15Min to heat up with no fans running and a gutted t/stat.
I was also only getting like 10MPG with my Q-Jet but i swaped to a Holley 600 im getting better fuel milage about 20MPG. but it don't have the same power that it did, it is also missfiring under load now.

What is open loop mode?