gears & gas mileage..............

[jrc_03_gt]

I have a 2003 gt . My mods are in my signature. I had 4.10's installed a few weeks ago. Most of my driving is city driving. I have only been getting about 80 miles per half tank of gas. This may be the result of my driving style. I dont trash my car but I do get on it every now and then. I dont race it on the road or the track. Is anybody getting the same results as far as gas milage? Maybe I need to granny shift it and use 5 gear more for better gas mileage, but thats no fun. I still love it and would not go back to stock 3.27's.

 

[XTONKAX]

Sounds about what I'm doing. Although, the last two fill-ups have netted me ~180 miles to the tank. That's up from the 120 I've seen.

 

[2k2fourpointsix]

I went from 230-250 to 200-220 tank after my 4.10's But I would never go back.

 

[jrc_03_gt]

I very rarely get it out on the freeway. I bet that is a major factor in my 160 miles to a tank.

 

[jrc_03_gt]

Sounds about what I'm doing. Although, the last two fill-ups have netted me ~180 miles to the tank. That's up from the 120 I've seen.

Do you run 87 octane? I do. I have no pinging or knocking so I use it. The owners manual calls for 87 octane too. Does anyone get better mileage with higher octane? My timing is still at the factory specs. I know people with timing adjusters have to run high octane. With a stock 4.6 motor can I increase mileage by going to high octane?

 

[claytucc3]

I noticed about 2 miles less per gallon with 373's

 

[CrazyHorn]

My opignion is that if the manual says 87 than I go with 87, the higher octane wont do any significant difference, because your car dont need it, if it was a car like my old civic siR(b16a2) than going to 87 would make quite a difference in performance and gas millage, also can make the engine knock, they recommend 91 for my civic.

 

[pdl2flr]

Do you run 87 octane? I do. I have no pinging or knocking so I use it. The owners manual calls for 87 octane too. Does anyone get better mileage with higher octane? My timing is still at the factory specs. I know people with timing adjusters have to run high octane. With a stock 4.6 motor can I increase mileage by going to high octane?

I tried a couple tanks of premium and my car seemed sluggish and mileage was worse. I went back to just using regular and my car seemed much happier. There is no benefit to using Premium fuel unless your car requires it!!

 

[claytucc3]

Your computer is programmed to run on 87 if you use anything else it will knock and just be a waste of money. If you have a custom chip chances are that it reptrogrammed your computer for a higher octain so then you need to use premium

 

[BMan5150]

Wow. . . I really hope this doesn't turn into another octane thread.

I drive my mustang year-round in mixed driving - about 50/50 hwy/city. My gas mileage is almost the same as it was with 3.27s. I'm averaging about 19-20 mpg and I've had 4.10s for about a year. I was pleasantly surprised to see that my gas mileage hasn't gone down much at all. I may get about 1 mpg less than with 3.27s, but even that's probably high because I was averaging around 18.5-19 in the winter with 4.10s and only 17.5-18 with the 3.27s.

140 per 1/2 tank and around 270 before the llow fuel ight goes on. Then I still have around 2.5 gallons left at that point.

 

[BMan5150]

Your computer is programmed to run on 87 if you use anything else it will knock and just be a waste of money. If you have a custom chip chances are that it reptrogrammed your computer for a higher octain so then you need to use premium

A stock mustang 4.6L will not "knock" if you run a higher octane than the manual requires.

Guess I just turned this into an octane discussion . . .

 

[Cobra Jay]

Your computer is programmed to run on 87 if you use anything else it will knock and just be a waste of money. If you have a custom chip chances are that it reptrogrammed your computer for a higher octain so then you need to use premium

I burn Amaco 87 but once ever 4th fill up I'll burn a tank of Amaco 93 just to clean the fuel system out. I havn't noticed any spark knock or anything else. If you run lower octane than what you should, that's when you'll notice knocking. My mileage doesn't seem to be any different between running 87 or 93 either.

 

[awwyea]

Wow. . . I really hope this doesn't turn into another octane thread.

I drive my mustang year-round in mixed driving - about 50/50 hwy/city. My gas mileage is almost the same as it was with 3.27s. I'm averaging about 19-20 mpg and I've had 4.10s for about a year. I was pleasantly surprised to see that my gas mileage hasn't gone down much at all. I may get about 1 mpg less than with 3.27s, but even that's probably high because I was averaging around 18.5-19 in the winter with 4.10s and only 17.5-18 with the 3.27s.

140 per 1/2 tank and around 270 before the llow fuel ight goes on. Then I still have around 2.5 gallons left at that point.

That's what I run BMan.... I do notice however, a reduction in mileage to about 220 a tank when I consistantly keep the rpms above 2000. If I do the "fuel economy" driving as recommended in the book, I can get 285-300 to a tank. Gotta admit though, rolling in the lower gears sounds so much better with higher rpms... guess ya gotta decide if you want it to sound good or to save $ on fuel.

I have a custom chip & 4.10s. I must admit the costs of my fill ups is more painful than it used to be !!!

 

[XtorT'r]

I drive like 100 miles a day if I used 4.10's I'd be broke. lol, Gotta love getting 320mi per tank, and I can still run like hell on the move. I do admit I am curious how much fun 4.10's would be, but I think I wont do it until I get an work site assingment thats not 50 freekin miles away or worse.

 

[XTONKAX]

Do you run 87 octane? I do. I have no pinging or knocking so I use it. The owners manual calls for 87 octane too. Does anyone get better mileage with higher octane? My timing is still at the factory specs. I know people with timing adjusters have to run high octane. With a stock 4.6 motor can I increase mileage by going to high octane?

Diablo Predator mandates my 91 octane. That's the highest available in my area.

 

[Modular2v]

i ran 93 octane at the track and netted my worst e.ts.....i have been experimenting with this for some time now and found my best times were when running 89 octane! but weather and track conditions could also vary

 

[01 Yellow GT]

I use 89 because it is cheaper and I have never had any problems. The only difference between it and 87 is ethanol.

 

[jrc_03_gt]

Wow. . . I really hope this doesn't turn into another octane thread.

I drive my mustang year-round in mixed driving - about 50/50 hwy/city. My gas mileage is almost the same as it was with 3.27s. I'm averaging about 19-20 mpg and I've had 4.10s for about a year. I was pleasantly surprised to see that my gas mileage hasn't gone down much at all. I may get about 1 mpg less than with 3.27s, but even that's probably high because I was averaging around 18.5-19 in the winter with 4.10s and only 17.5-18 with the 3.27s.

140 per 1/2 tank and around 270 before the llow fuel ight goes on. Then I still have around 2.5 gallons left at that point.

Wow that sounds too good to be true! You must drive your stang like a granny. Just joking. I'm above 2000 RPM'S quite often. Mybe it's just my heavy foot. But its really fun!

 

[Dark Knight GT]

What is wrong with you guys gas mileage ? I have a 2001 automatic GT with all the mods in my signature and on the local highway roads which has idiot drivers I have to stop/slow down for and all the hills included I can still get about 24mpg. I admit, I only have 3.27's in the rear but still, I've got a hell of a lot more mods in other ways than you guys and my car is yet to be tuned. Not to mention I'm still on the stock fuel filter after 21k miles.

 

[tjm73]

I went from 230-250 to 200-220 tank after my 4.10's But I would never go back.

230-250!!! I get 310 every tankl with my 3.27's and I'm thinking about going to 3.73's.

EDIT: and no I don't drive like a grandma.