AC vs Gas mileage - Diesel Forum

Testosterone · 07-09-2001, 03:24 PM

Has anyone have a problem with their gas mileage when running the AC? I haven't done any detailed comparisons, but I seem to lose about 1 mpg when running the AC. I would think with this big V10 it would hardly notice the compressor, doesn't seem to be the case.

twinbulls · 07-09-2001, 05:47 PM

I would also like to find out this info I live in south FL and always have the AC on and I get from 10.8 to 12.3 I have yet to drive with the AC off. Maybe if I go north or on a cool day this winter??

F-250 Hoss · 07-10-2001, 07:39 AM

I've never noticed a difference in mine. With the driving I do, I get a constant 12.1 mpg. It's been like this since it got hot enough to need the AC. At my old jobsite which required more stop and go type driving, I got 11.5 mpg, but that was not using an AC (it was winter).

dhahn · 07-10-2001, 11:52 AM

I do 95% percent highway driving between 75 and 85 mph. I put about 1000 miles a week on my truck and I get between 12.5 and 13 mpg with or without the AC.

Harald · 07-12-2001, 11:13 AM

This might be hard to figure out. The AC can run in all but 3 positions on the dial. I know off will shut off the AC and I believe the other two positions are straight air in the face or air to feet only. All other positions allow the AC to function.

With that said, I have never checked without the AC running. Most of my trips are from 1 to 6 miles on hilly terrain with many stops. So I only get 8.5 mpg with that lousy oxygenated winter unleaded. Best mileage ever was 13.5 using good fuel on the highway unloaded at 60 mph.

Foghorn · 07-12-2001, 03:13 PM

Make sure you're running with the AC on MAX. That way you are only cooling the inside air(adjust the tempurature control to a comfortable setting). With the knob set at AC you are cooling outside air - therefore the compressor will run more. I don't notice any mileage difference in the MAX AC setting. I get 14mpg on almost every tank [img]images/icons/laugh.gif[/img] -- most of my driving is highway or secondary roads @65-70mph with the AC in the MAX setting. Don't forget, with the windows down there is more drag [img]images/icons/wink.gif[/img]

John Z · 07-12-2001, 09:00 PM

I think the real mpg killer with the V10 is idling. I noticed the same 1 mpg difference with the AC myself, but the truck was brand new and I was still experimenting with it. I'm in Ft Laud. I didn't buy a $3xxxx truck to drive around without air so I don't pay it much attention any more. ONE thing I will STRONGLY recommend for hot climates is to get the side front windows tinted. Those are huge windows and tinting them really helps. I got what was represented as "legal" tint, I forgot the percentage. I was a bit concerned about night driving, but it has not been a problem. You don't even notice. I'd probably go for the "not quite legal" tint that matches the rear if I had to do it over again. It is also worth noting that Costco happens to sell a front window shade that is large enough for the Excursion, and also happens to be in tan color, for those with this common interior color.

twinbulls · 07-12-2001, 11:31 PM

You really want to know the REAL milage KILLER its my(our) FOOT!! I cant stop getting on it, especially when a new Chevy or dodge pull up net to me.Just like when I was a kid.... [img]images/icons/wink.gif[/img] But now I know when to slow it down..These Trucks just move out so well!!
I bet if I were to be a lot lighter on the pedel I would get much better milage #s like the PSD maybe??? ok well maybe not..
about sun shades I have one that pulls across the entire windshield and hooks on drivers side, more of a blind about $60.00 but it keeps truck a little cooler and i noticed it cools off faster..
Why are their 2 ac settings anyway ?? I never use the ac one only use ac max

Testosterone · 07-13-2001, 04:46 PM

Thanks for the responses, I will run AC only on Max over the next tank and see if that makes a difference, good point.

V10man · 07-15-2001, 11:36 AM

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by twinbulls:
Why are their 2 ac settings anyway ??<HR></BLOCKQUOTE>

As stated in an earlier post, the max AC setting recirculates inside air, where the regualr AC setting pulls in outside air. Typically I use the settings in this fashion. Since I am in AZ, it is HOT!!. Just startin g out, the inside of my truck will be hotter than the outside air. So my first setting is on regular AC. Once it cools down a little and the inside is cooler than the outside, the I switch to max AC to further cool down the interior. Now about a block from home I switch back to the regular AC setting. This "dries" out the ducting so that I don't get a musty smell. [img]images/icons/smile.gif[/img]

In between all of this AC switching I actually get some driving in... [img]images/icons/laugh.gif[/img]