mattbabino

I have a 94 Pickup with a 22-re with flex-a-lite fan and a K & N air cleaner and only get about 15 mpg's in town or on the highway. I have the stock gears and 33 12.5 tires could there be a problem that is killing my mpg's or is this normal

RedRunner_87

Probably the only way you are going to get better milage is to regear, so I would say that is normal. I was getting around 16 in my 4Runner with 31's. I also had the 22RE, 5-speed.

Paul H.

Yeah, your 33's are killing your milage.

trythis

It takes a lot of energy just to rotate tires that big.0, if you want better, you'll have to go smaller tires.

mattbabino

thanks guys i was just wondering if it was normal it didnt seam right to me dosnt bother me that much just wanted to know if there was something wrong or what ever but thanks alot

breesej

How are you calculating mileage? Are you including the multiplier that your larger tires give you in your mileage, or is it straight from the odometer?

I get 16MPG from the straight odometer reading, 18.5 corrected.

bodo

Yes I used to get 11 with 35's and 4.11's. You can't calculate MPG's when your speedometer/odometer is off. Now with a highly modified 22RE, 4.88's, and 36" tires I get 17.3 mixed.

Elton

my 22re 4x4 got 24mpg on 235s and it had some mods

jsnby

3.0, 35x12.5 bfg mt, bunch of other crap...

mattbabino

im couculating it through my odometer so thats wrong becuase i have biger tires on it now how do i figure it out another way??

misterzee

I would think with 33's you'd be a little frustrated with the lack of performance, also perhaps getting ready to buy a new clutch LOL.

Elton

also take in fact ur speedo is going to be off

breesej

stock tire size is 225/75-15 I believe which makes the tires roughly 28.3" tall

Here's the formula:
((new height - stock height) / stock height) * 100 = percentage difference

Here's your values:
((33 - 28.3) / 28.2874) * 100
becomes:
(4.7125 / 28.3) * 100
becomes:
.16659 * 100
becomes:
16.659%

Take your odometer mileage and add 16.659%, this is the actual mileage driven.

In my case, I have 32" tires which is 13.125% over 225/75-15 tires which is the stock size. Some trucks came with 31's but I'm not sure if the speedometer and odometer were calibrated to 31" tires on those models.

Hope this helps

breesej

I forgot to add that your corrected MPG's is probably around 17 or 18 MPG

bodo

You can use a GPS or change your axle ratio to compensate for the larger tire which would make your truck alot happier.

BigWavePaul

iTrader: (1)

I use 31's and wanna know how to make the Speedo/Odometer read right. Is it a lunchbox gear swap or what? Can I do it myself in the driveway?

mattbabino

i went by one of those radar things the cops put by schools to tell you how fast you are going and it was only like 2 or 3 miles off which surprised me

breesej

2 or 3 mph at what speed? Your speedometer is not the most accurate device, so take it all with a grain of salt.

bodo

Your speed will not always be 2-3mph off it will be a percentage off. Use 10% for an example at 45mph your speedo will be off 4.5 mph which probably won't get you a ticket, but let's just say your on the interstate and you're doing 75mph that's 83mph and the FHP loves them ticketbooks. Now with 31's it's not that bad but 35's it's bad. Oh and those stupid radar trailer things aren't accurate at all, I've seen one say my yota was doing 73 and my speedo said 25mph.

breesej

You must have really big tires