MPG thread

[SWRT]

So, I have two Festiva's. Both 5 speeds. Just got them both. The blue one has A/C and the red does not. So I filled up the blue car and drove with the A/C on the 2 setting the whole time and got 41 MPG and I was ecstatic! Then I drove the red one without A/C and drove it exactly the same and got 49 MPG. Does A/C really account for an 8MPG loss?

[M3NTAL]

Wow 20% that's a lot.

[Movin]

The type of Freon, AC charge, clean condenser, Working ac radiator fan all will affect mileage. Engine condition, tune condition, exhaust condition are some of the nuts and bolts things that can affect mileage a lot. Ambient variables will also affect mileage a lot and you did not have a second driver follow so as to more closely duplicate driver variables? One trip each means nothing was averaged..there is just too many variables to hazard a guess toward an accurate number for the difference. But of course there is a difference.

[TominMO]

Also, you didn't say how far you drove on these tests. The shorter the distance, the more inaccuracy can creep in when filling the tank, before and after the test.

[SWRT]

Well, the driving distance was exactly the same. To and from work every day.
The shift points were stretched by maybe 2 miles per hour in a few gears to make
up for the draw of the AC. Seems like there's a big difference either way, but I guess
once I install the new parts I'll be able to get a more educated guess from them. I was
just kinda shocked at the initial difference. Unfortunately I'm not driving the blue car til
I get the throwout bearing changed out as it's rattling pretty badly, but when I do I'll
update this thread and let you guys know how it turned out.

And I'm willing to bet this is the original R12 in there. I was considering a 134 conversion,
but I've heard it can potentially eat seals and stuff. Not sure on the validity of that. Also heard
there's propane-based freons you can use, but I dont think I like the idea of a potential leaking
of propane into the engine bay.

[jayber]

Drive the AC car with the ac off and see how much it picks up for comparison

[eurotiva]

I got 22 mpg towing the aspire...

[Pu241]

Got 31 MPG towing a '81 VW diesel Rabbit through the mountains of WV/MD/VA about 400 miles.

[harpon]

I generally switch the air OFF if I'm starting out in traffic, especially up any rises, or hills- and it makes a difference in acceleration-

so, yes, I think A/C significantly lowers mileage- however you CAN do simple shut offs at certain times to minimize it.

[SWRT]

I guess I could run it one tank without the AC to see the difference, but there
will be variables anyway as I'll be replacing other engine and suspension parts so
I dont know how accurate it will be either way. I'll see what it is without AC and
then with AC on the same car.

I make my wife do that in the Forester every time she gets on the highway. I'll
try it when I go to start off of lights til I get up to speed and put it back on and
see how much that helps

[Movin]

^^^ so...even if we are just towing a diesel we get better mpg's lol

[SWRT]

Well, and the turbo car towing an Aspire got better MPG's than my Legacy haha

[bhazard]

Yeah I get between 30-38 mpg towing with my Golf. Depending on AC usage. Its fun passing the big truck guys while doing so.