22MPG?

[mhanksii]

OK so I am on vacation and made this 1092mile trip. Over this whole trip I set cruise between 65-75mph the whole way (minus a run in with a Camero SS). I have never gotten such bad gas mileage out of my pony before. The only things that I changed were my tires (245/45 f 255/45r Fuzion ZRI) and my shifter (Hurst Short throw). Why would either of these change my normal 24.5-25mpg so much? Oh and I know it hurts performance but it was over 90 degrees outside the whole trip.


Any advice or insight is welcome and much needed. Thanks

 

[MikeysOTP]

OK lets get to the important part first! How did you do against the Camaro? Sorry to be :OT: but you left out the best part.

 

[JuJu_GT]

Well, the shifter definitely would not have affected your mileage. So, that leaves the heat and the tires. Sounds like your tires are a little wider now (more rolling resistance), plus if they are heavier than the outgoing set, your unsprung weight has increased which would negatively affect efficiency & performance. If the tires are only negligibly wider/heavier, then I would say the heat played a bigger role in the decrease. However, it is probably some mix of the two.

Cheers!

 

[Kilmar]

I'd be jumping for joy if I can even get NEAR 22 MPG. Pushing 10-12 at the moment. And what happened with the SS?

 

[bigcat]

check your air filter.

 

[JTGrant]

What about the SS?

 

[ranger04]

22 mpg is what I'm getting locally, I haven't been on a trip yet. I thought 22 mpg was awesome for a 300 hp car. My 68 GT with a 428 CJ, 4-speed and 3:90 gears would only get 11 and it was rated at 335 hp, so I'll take 22 all day long. The temp will have an adverse effect on mileage in the hot summer months for sure. When I first got my ranger 4x4, I was getting 18/20, I switch to all synthetics, a bama programer, cai, udp and catback, now I'm at 22/25. Bama and the synthetics seem to help the most, however this last week whens it's been so hot, I dropped back down to 19, humid air does suck.

 

[stanmckinney]

I'm getting about 22 also on the road. I've read on these forums that at least one person is getting 30. BS, I say.

 

[DarkFireGT]

I'm getting about 22 also on the road. I've read on these forums that at least one person is getting 30. BS, I say.

I don't think it's impossible. Off the lot, I drove an hour on the highway at 78 MPH and got 28. If I was doing the same thing on a 55 or 60 MPH road in 5th gear, it's totally doable, especially with the car being broken in and having an intake and tune.

 

[seal614]

I have the feeling that people (who talk 25+mpg) are reporting what their gauge cluster tells them.

I hope you guys are actually calculating when you fill up, the cluster has been off for me (and usually high) by 2-3mpg every time.

 

[MikeysOTP]

I have the feeling that people (who talk 25+mpg) are reporting what their gauge cluster tells them.

I hope you guys are actually calculating when you fill up, the cluster has been off for me (and usually high) by 2-3mpg every time.

I hope my computer isn't 3mpg over, that would put me in the low 11s

 

[V8JamesGT]

Last night on my way to work I reset the mpg on my gauge cluster when I got to 5th gear and got 30mpg on a 12 mile trip. With some UD pullies and aluminum DS I could do even better. But like others have said... I'm not sure how much its off.

 

[SlideWRX]

My gage cluster is within 0.5 mpg on a tankfull. Over a ten mile stretch, I was able to maintain 28 mpg going 50-55 mph. I've done some longer stretches at 26+, again below 60 mph. The aero drag seems to become significant around 60 mph.

mhanksii, what tire pressures are you running? That can easily be an mpg or two. Also, with the stickier (usually lower profile) tires, an alignment closer to zero toe improves mileage.

Tom

 

[mhanksii]

SS, hhmmm Super Slow maybe?

OK so the question I read the most on here in response to my question is, how did I do against the bow tie. Simply put I smoked him like a cheap cigar. We would slow to 55-60mph, he honked and we dropped gears like they were going out of style. I have to say that power shifting with a short throw Hurst is a HUGE rush! I would only pull a car or so on him and it would happen right of the bat, but I could hold my lead and we ran all the way to 135. We both quit there and boy am I glad because my pony was grunting and trying but didn't want to go any faster. By the was just for good measure we ran 4 times with the same results every time.

Now for the tires, I check the weights (both online and with a scale) and the fronts are each 1.5lbs lighter and the rear about 1/4lbs lighter as well. I didn't think about the rolling resistance going form a tread wear 400 235/55 to 320 255/45. That does make sense, it just scared me because I do calculate my mileage and the cluster is usually within 1mpg at 20-23mpg around town and such. There is a lot of smoke and missing tread in that driving too, so I was really hoping for something like 25mpg on the highway just cruising.

I think it was Big Cat who said check the air filter and man it's horrible, to the point I think I am done cleaning it and going to replace it. Thanks to all who weighted in.

 

[bigcat]

I think it was Big Cat who said check the air filter and man it's horrible, to the point I think I am done cleaning it and going to replace it. Thanks to all who weighted in.

a dirty air filter can kill your mileage faster than most other "simple" things. tires, weather, etc can have an effect, but if a recent trip is not as good as most other trips, usually a clean filter will cure the problem. glad to help.

 

[mhanksii]

a dirty air filter can kill your mileage faster than most other "simple" things. tires, weather, etc can have an effect, but if a recent trip is not as good as most other trips, usually a clean filter will cure the problem. glad to help.

Big Cat if you ever write a book on these S197's let me know I will be your first customer. You have great advice and good write ups on upgrades. Thanks again to you and all the forum guys for advice and sharing knowledge.

 

[welchy]

I know this is a Mustang site, but a car gut should really know how to spell Camaro.

 

[Edcyclopedia]

a dirty air filter can kill your mileage faster than most other "simple" things. tires, weather, etc can have an effect, but if a recent trip is not as good as most other trips, usually a clean filter will cure the problem. glad to help.

Let's not forget air pressure, aluminum rims expand and contract to lose air on a regular basis, I check my pressure evry 1-2 weeks.
Glad to hear that the stang ran past the SS Charo, gochy-gochy!

 

[stanmckinney]

Don't want to get into another issue here, but we should not be encouraging racing on the street. Take it to the strip. Some young people in my area were killed just a couple of days ago because of another driver going too fast.

 

[wwar1ace]

Taking your trip when it's 90 degrees outside can screw you over at the pump too, if you're filling when it's still hot...

The pumps are calibrated for a certain temp, and don't automatically adjust to changes in liquid density, so you'll be getting less fuel for your gallon when filling-up after a day's heat.

Another thing to consider is the landscape... if you're crossing mountains, don't expect the best mileage. My best is about 25 MPG, but that's on the flat.


-wwar1ace

OK so I am on vacation and made this 1092mile trip. Over this whole trip I set cruise between 65-75mph the whole way (minus a run in with a Camero SS). I have never gotten such bad gas mileage out of my pony before. The only things that I changed were my tires (245/45 f 255/45r Fuzion ZRI) and my shifter (Hurst Short throw). Why would either of these change my normal 24.5-25mpg so much? Oh and I know it hurts performance but it was over 90 degrees outside the whole trip.


Any advice or insight is welcome and much needed. Thanks