Looking to improve gas mileage a bit

[ESVEETEE]

I currently drive 500-600 miles a week back and forth to work in the cobra.

I'm looking to improve my gas mileage. I currently am averaging 20 mpg @ 80 mph. My commute is maybe 90% highway/interstate.

My mods are in my signature and I'm currently running the factory tune.

Would it be worthwhile to get a tune, would my MPG increase enough to outweigh the cost of a tune? Also, what is the best speed to drive for gas mileage with 3.73s?

I should mention I can't afford another car right now, but I'm spending about $400/month in gas.

 

[1BD9D7]

You will do much better on gas mileage running 70 instead of 80, but it probably is not practical. I can't imagine putting that kinda miles on one of these cars, in 2 weeks you do the same amount of driving your car as I do in a year lol. I am sure at 80 mph you would gain 2-3 mpg if you switch back to 3.27 gears, I doubt a tune is going to help mpg much, maybe I am wrong on that though.

But damn I would avoid some of that driving if I could - find someone to carpool with! (Sure you hadn't thought of that ) good luck

 

[mwolson]

I agree on both the gears and slower driving. A tune can also help.

There is a forum over on Corral that you may find some good info in: Green-Rodding - Ford Mustang Forums : Corral.net Mustang Forum

One thing I know is that a tune that is optimized for fuel economy is not optimized for good emissions. I suspect your NOx emissions may go up quite a bit with a tune for economy.

 

[xblitzkriegx]

my 97 vert is completely stock. i just avg'd 24mpg at 80mph in texas on a 400 mile round trip for the holidays. that was with some spirited passing (110+) and a little in town stuff mixed in. 90/10, hwy/city.

swapping to 3.27s will help. a tune that runs a lil lean will help. most importantly, make sure the car is in good mechanical condition.

 

[mustang3X]

you'll need to drop to a 2.73 to see any appreciable gains in mileage, you'll also have to creep along at 70.

Best option is to buy a used focus and use that to commute, you can find good ones for 2 to 4K. If you are spending $400 per month in gas only for the cobra the focus will pay for itself in as little as 1 year.

In addition you keep the wear and tear off the cobra which helps its value.

 

[jmsa540]

Honestly, I think a tune would benefit you. Think of it as a 17 year software upgrade. (Like going from Windows 95 to Windows 8.1) Hey, nice tranny by the way!

 

[CzchMex]

It's all about how you accelerate. I have a semi stock Cobra and used to get 22mpg on the highway with lots of driving. Now I get 18mpg because I drive it for fun now.

I still have stock 3.27s. However shift before 2,000rpm (1,500 if you can) and sometimes skip gears (1-3-5) or (2-4-5-)

But good luck on trying to get better than 20…I see that as good.

 

[jmsa540]

Yeah, I see 20mpgs as good too..

 

[1BD9D7]

My first 97 cobra was well over 100k miles and basically all stock, still had 3.27, it would get 20-25 no matter how it was driven, yes 25 is possible in these cars.

My current car has 3.73 and a vortech, I still get close to 20, I believe I could be over that 20 mpg if I shifted before 2500 rpm or so, staying out of boost...for some reason I have never been able to test that hypothesis.

 

[mwolson]

staying out of boost...for some reason I have never been able to test that hypothesis.

Me neither! :beer:

 

[ESVEETEE]

I typically shift at 2200. However 85 is 3000 rpms.

I'm going to look into the tune because I think the imrc deletes hurt my mid range power costing me a few mpg.

I'm even running 245/45/17 on all four corners.

My car consumes oil pretty decently. I'm adding maybe 2 quarts each oil change. I should probably do a compression test to see how the rings are doing.

I tried slowing down but the hills make it tough to go too slow and my gas mileage didn't change. I couldn't imagine going up a steep hill with 3.27s or 2.73s at 70.

 

[jmsa540]

man.. 2 quarts.. goodness!

 

[stiffler197]

Best way to improve gas mileage is buy a commuter car lol. It'll pay for itself in fuel savings and you can keep miles off the cobra

 

[busta]

Don't forget to check your tire pressure

 

[SNAKEYE]

I'm adding maybe 2 quarts each oil change. I should probably do a compression test to see how the rings are doing.

Have you tried using a heavier weight oil?

 

[ESVEETEE]

Currently running 5w-30. I was thinking about stepping up to 10w-30 or 10w-40.

 

[mustang3X]

Currently running 5w-30. I was thinking about stepping up to 10w-30 or 10w-40.

Changing weight will do nothing, your engine burns oil and it needs to be fixed. Until you do that, nothing is going to improve.

 

[SNAKEYE]

You can also try an oil additive that will cleanse sticky rings to help them seat properly. Along with a higher viscosity oil for the next change.

 

[ESVEETEE]

Update: the tune had no effect on gas mileage.

However I played with my speed a bit. 70 mph: 20 mpg
80 mph: 20 mpg 90-95 mph: 22 mpg


WTF

 

[AZSN95SNAKE]

You've got the wrong car for gas mileage lol especially with gears. I've been getting 18mpg with mixed driving and 4.10s. I have a tune, and it didn't do squat for mileage but that's not what I got the tune for.