16 MPG? Suggestions?

[BROKINBIMMER]

No autotragic...5 speed. I have read that with an auto trans one should still get @ 22 mpg in the city.

So you swapped the diff with a 4.10? I will be doing a 5speed conversion soon and was worried that my gas mileage will get even worse...

[dnguyen1963]

No autotragic...5 speed. I have read that with an auto trans one should still get @ 22 mpg in the city.

[BROKINBIMMER]

Even in city, I average 24 mpg through out the year. Hot summer does not affect mpg much at all. Something is wrong with your car if 14 mpg is the best you can get.

Do you have an auto trans with a 4.10 rear?

[dnguyen1963]

Sorry, mis-read your post. You did say 14 mph.

[dnguyen1963]

Even in city, I average 24 mpg through out the year. Hot summer does not affect mpg much at all. Something is wrong with your car if 14 mpg is the best you can get.

[ELVA164]

Just realized the post above me isn't from OP, but it's still true. OP, when you say it runs "a bit hotter," are you just using the gauge to determine that? Like Jim said, you should check the temperature of the head with an infrared/contact thermometer and make sure it matches your thermostat.

[ELVA164]

Not for anything, but the low speed by itself is going to destroy your mileage. Right now, with temperatures in the 40-60deg F range, I'm averaging 28-30mpg in mixed conditions. You unfortunately have a lot less control over mileage with an automatic transmission, but at 10mph things won't be getting much better no matter what. As a side note, my OBC was almost spot-on the last three tanks I've checked using distance/volume consumed.

[Quinthirty]

Why would it be unattainable? I routinely get 30 mpg on the hwy.

This is why I specifically mentioned "in our conditions" because I live in the city and don't have a lot of highway runs. I'll probably achieve that only if I do out-of-town trips and close to pure highway runs, but still doubt it. I haven't even factored warmer average temperatures which affect mpg performance too. SF weather averages in the 50s-60s vs. our high 80s-90s year round.

Imagine this: The average speed that I get on a full tank of gas is roughly 10mph. It can probably go up to 14mph if traffic is "better." That means a lot of low gear runs.

[digger]

mods delete this wrong spot

[BROKINBIMMER]

And just a small update, the car definitely runs a bit hotter with the new thermostat.

[BROKINBIMMER]

Thermostat is in, TBD if its in correctly.


And yes, I always calculate mileage by distance traveled rather than using the computer.

[Regnar75]

so just wondering but is your MPG's what your computer is saying or what you calculated? because i went on a 145mile roadtrip in my 86 ES with CAI and Mark D chip, and i got 39MPG (based on gas used from fill up to fill up) at 80mph. all the while my computer was telling me i was getting 27MPG.

[jlevie]

The thermostat goes in with the pyramid shaped end out. If there isn't a hole in the thermostat plate there won't be an arrow to indicate which way is up. Drilling 1/8" hole in the plate and positioning it up will make bleeding a bit easier, but isn't necessary.

[BROKINBIMMER]

Ok, I have the thermostat and housing removed. Here's the problem, the new thermostat has no arrow....HELP!

[dnguyen1963]

This is my average after all the improvements. But the traffic conditions I travel on are very hot, 70-80% traffic, 20% highway (short runs) only. Makes me envy you guys who average 22. Saw Bernzpeed's 29mpg which I think is unattainable for an M20B25 in our conditions. Running an A/T with 4.1 too.

Why would it be unattainable? I routinely get 30 mpg on the hwy.