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mileage with 33s and stock gears?

SeansXJ

NAXJA Forum User
im on 33s with stock 3.55s and im curious how off my milaeage is. anyone have a link? i did search but maybe im missing it because i can't find anything on 33s just 31s which i have read its about 11 miles to every 10.


thanks in advance
Sean
 
its a ratio, not really a number...
at the speedo 55mph, i'm really going 65 on the same setup,
lower speeds are a lot closer to the speedo
i just use a handheld GPS on longer trips to know how fast i'm going, just stick it on the dash and call it good, hope this helps
 
its a ratio, not really a number...
at the speedo 55mph, i'm really going 65 on the same setup,
lower speeds are a lot closer to the speedo
i just use a handheld GPS on longer trips to know how fast i'm going, just stick it on the dash and call it good, hope this helps

thats kinda what i figured there...


im thinking for every 10 miles on the od add an extra 2?
 
On the highway I get 20-21mpg at 60-65mph with 3.55's on 31's. This is after ford 19 lb/hr fuel injectors though, that brought it up 2-3 mpg.
 
im getting roughly 12-13 mpgs in town right now, new cap/rotor/plugs/oil change...not too bad considering stock gears and 33s
 
I get about 12-14 mpg with 33's and stock gears. It works out around 210-220 miles when the light come on and I reset my speedo and my gps with every fill up. It's gonna be a little off because in NJ we don't pump our own so sometime they top it off a little and sometimes they don't. My GPS to speedo can be off as much as 50 miles on long highway trips
 
My speedometer is typically 5 mph lower than actual speeds with 33's and 3.55's.

As far as mpg, it really depends on the type of tire. With 33" a/t's I got 18-19 mpg on the highway, with my tsl's it's more like 12 mpg. I think it has a lot to do with the weight of the tire. The a/t's must weigh about 1/2 that of the tsl's.
 
No my math is right, but it's a good bit lower around town. And I don't use a heavy foot. Until I burn up this tank, I won't know exactly what my overall mileage is.

I did the fuel injectors for better throttle response and smoother idle. I didn't expect any mileage gains. But search around for mustang fuel injectors. My old injectors were not in good shape at all though, the ford ones looked much better.

My speedometer is typically 5 mph lower than actual speeds with 33's and 3.55's.

As far as mpg, it really depends on the type of tire. With 33" a/t's I got 18-19 mpg on the highway, with my tsl's it's more like 12 mpg. I think it has a lot to do with the weight of the tire. The a/t's must weigh about 1/2 that of the tsl's.
I have a/t's as well, so less rolling resistance than some of you.
 
i have 33" xterrains, and the 19lb ford injectors, but i still only get 10 in the city and i have a horrible idle. must have other problems, hope things go well
 
When I had 33's and stock gearing I was getting about 13mpg.
I haven't checked since I got 4.56's lockers and it became was no longer the DD
 
With 30s and 3.55s, my speedo was dead on. Odo read about 80% of actual mileage. Now with 33s, my speed is off by about 10% from the 30s. Don't know on the odo. So at an indicated 45, I'm actually doing 50 (50-10%=45). An indicated 59=an actual 65. I confirmed my math using my GPS. Haven't done the actual mileage yet though. Gears will be going in soon though.
 
With 30s and 3.55s, my speedo was dead on. Odo read about 80% of actual mileage. Now with 33s, my speed is off by about 10% from the 30s. Don't know on the odo. So at an indicated 45, I'm actually doing 50 (50-10%=45). An indicated 59=an actual 65. I confirmed my math using my GPS. Haven't done the actual mileage yet though. Gears will be going in soon though.

how could the speedo be correct but the odometer be 80% off?
 
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