First Hwy Run... Fuel Economy Report

[bestwheelbase]

Originally Posted by gily25

Honestly this was my one reason for justifying the purchase of a lightweight car (gas savings), it just happened to come in a sports car package with a few extra smiles, "mpg with style" eat that accord and elantra.

Same here. Fun and sporty without the guilt of 15mpg and having to refuel every 3 days. And it's not just about the dollar amount. It's about the whole experience.

[gily25]

Originally Posted by bestwheelbase

Same here. Fun and sporty without the guilt of 15mpg and having to refuel every 3 days. And it's not just about the dollar amount. It's about the whole experience.

I was about to buy a Jetta......and then I was questioning whether I should just GTI and forget about mpg when I stumbled onto the 86. So glad the dealership closed early that day lol.

Answer above comment about terrain...I would say it was average...Hartford-Boston then Boston-Hartford same highways.

[A5D5TRYR]

Originally Posted by Dadhawk

A/C makes a difference but I don't think it would make that much a difference.

What isn't mentioned (or if it was I missed it) in the OP is whether or not both legs were on the same/similar terrain. That could also account for the difference.

If you go to my Owner's Journal I have all my mileage there documented by tankful. Looking through it I don't see a significant difference between winter months (no A/C) and summer months (A/C all the time).

June/July/August, I averaged 31.76MPG with all A/C all the time. Dec/Jan/Feb I averaged 32.58 with no A/C. 90% of my driving is done on the same roads at the same time of day in both occasions. There would have been a difference in fuel mix (summer vs winter blend).

The other difference between summer and winter driving is that in the winter it takes much longer for the engine to warm up and in that extra time you will get much worse mileage than once the engine warms up. If you're making long trips this effect will be much less pronounced but it is still there. Might be that the fuel saved by warming up quicker is being used up by the A/C.

To be honest you have to figure that the A/C compressor can't be robbing more than a couple HP at MOST. Although now that I think about it you only need a handful of HP to maintain speed on the highway.

Just for the fuck of it lets do some keyboard warrior math based on pure conjecture (why?... because it's fun and someone will probably try to argue it even though I have absolutely no facts here at all ).

If we assume the car needs ~15 HP to maintain speed and also assume that the A/C robs 1/2 HP then this would be about a 3% loss in mpg. At 32 mpg that is right around 1 mpg. Hmmm... for pulling numbers out of my ass that actually comes out to about the difference I would expect from using A/C on the highway. Yay for me. Hope someone else enjoyed this useless post as much as I enjoyed making it.

[tuckdaddy]

Originally Posted by Freeman

31,000 revs? either a typo or you did some magic.

v-Tec yo!

[immortal_suby]

I'd be very surprised if the parasitic AC was enough to cause a mileage drop vs. the aerodynamic drag of having the windows open.