tire size effect on guages

[paintballdude902]

so im thinking about getting a bronco for offroading and i will be putting a 2-4" lift on it plus some tires probably 32-33 actuall

what will the change of tire size do to the speedometer and odometer

 

[Seabronc]

Adding larger ties will make your speedometer read low. What year truck do you have? Some have speedo gears and newer ones have a speed transducer and can be altered to compensate for the tire change.

>-

 

[Broncobill78]

so im thinking about getting a bronco for offroading and i will be putting a 2-4" lift on it plus some tires probably 32-33 actuall
what will the change of tire size do to the speedometer and odometer

You won't need a lift to run 32-33 tires. 4" will get you to 35's. Tire size wil throw off the speedo but you already knew that when you asked. IF you buy one & IF you lift it then go to a local or online speedo shop & get a new speedo gear that will correct it, no big deal everyone carries them or just know that you're reading slow & don't drive fast on big tires w/a lift since you're already top-heavy to begin w/t. Any speedometer shop can correct it for you.

 

[paintballdude902]

You won't need a lift to run 32-33 tires. 4" will get you to 35's. Tire size wil throw off the speedo but you already knew that when you asked. IF you buy one & IF you lift it then go to a local or online speedo shop & get a new speedo gear that will correct it, no big deal everyone carries them or just know that you're reading slow & don't drive fast on big tires w/a lift since you're already top-heavy to begin w/t. Any speedometer shop can correct it for you.

well the whole story is i got broad sided about 2 weeks ago driving my dakota(not my choice of car im 17 and we had it)

but ive been told by the guy at the body shop that he is pretty sure it is totaled just becasue of the man hours and parts will total to 5000+ and thats about the value of the truck

i have had a love affair wiith broncos since i was little and my dad sold his

but i dont want to lift it too high because ....welllll....im 17 and dont want to roll lol

i am probably gonna do a 2.5 incher and then some 32 actuals or maybe some 33 advertised

but i dont want to go much bigger than that because it will ****** my milage

any one know how much 35s take away form ur milage?

my friend driver a blazer with 35s and a skyjacker and he gets 9mpg

i figure that 32-33 will get me thru most anything i need for a hunting truck with the occasional mudding

 

[Broncobill78]

well the whole story is i got broad sided about 2 weeks ago driving my dakota(not my choice of car im 17 and we had it)
but ive been told by the guy at the body shop that he is pretty sure it is totaled just becasue of the man hours and parts will total to 5000+ and thats about the value of the truck

i have had a love affair wiith broncos since i was little and my dad sold his

but i dont want to lift it too high because ....welllll....im 17 and dont want to roll lol

i am probably gonna do a 2.5 incher and then some 32 actuals or maybe some 33 advertised

but i dont want to go much bigger than that because it will ****** my milage

any one know how much 35s take away form ur milage?

my friend driver a blazer with 35s and a skyjacker and he gets 9mpg

i figure that 32-33 will get me thru most anything i need for a hunting truck with the occasional mudding

Way too many questions to answer until you actually have one in your driveway, you could wind up with a 300, 302, 351 or 400 depending on what year & options you pickup.

You won't need a lift to run 33's and it's probably not worth the hassle/expense of swapping speedo gears for those tires. If you want to run 35's plan on a 6" lift if it's an 80-96 or 4" if it's a 78/79

35's will ding your milage but you can swap gears and get some of it back but plenty of guys run up to a 36" without changing the gears (probably run you at least $2500 to change front & back and you'll have to own the truck for a while to recoup that in fuel savings)

I personally wouldn't bother with a 2.5" lift just to run 33's. TTB lifts are kinda pricey and I'd wait to commit to at least 4" to 6" before I dropped the coin for one & don't forget how much a set of 35's + rims is going to cost. Tires, rims, lift & shocks will run you at least $4K before you're done with it and probably more if you're paying anyone to work on it.

 

[Seabronc]

any one know how much 35s take away form ur milage?
my friend driver a blazer with 35s and a skyjacker and he gets 9mpg

That all depends on what size tires were there in the first place and if the speedometer was accurate at that time. An easy way to find out how inaccurate his speedometer is, is to get on a major highway and drive 10 miles per the mile markers, (they are very accurately placed). Note the mileage at the start and note the indicated mileage at the 10 mile point. The advantage of this over driving one mile at 60 mph is that you don't have to drive at any particular speed and the distance will give a more accurate number. You could drive it at 10 MPH, 95 MPH or any variation of speeds and it will give you an accurate number.

So for ex. if you go 10 miles per the mile markers and your Odometer said you went 9, your reading 10% low. With that information in hand you fill up, noting how many miles your odometer said you went since the last fill up, lets say it said 280 miles, 10% of 280 is 28 miles, add that to the the indicated miles to get 308 miles traveled. Or apply it to the last MPG calculation of sat 10 MPG and WALLA, you are getting 11 MPG. Or add 10% to the indicated speedometer indication, did he ever get a ticket for speeding when his speedometer said he was OK?

Also from that information you can decide what speedo gear. Ford speedo gears change the reading approximately 7% per tooth added or subtracted. Reducing the tooth count increased the indicted speed approximately 7%

An alternative would be to use a GPS then you can check it any where and at multiple indicated speeds and it will be telling you exactly what you are doing without any personal involvement in the calculation.

Hope that helps you,

>-

 

[Broncobill78]

That all depends on what size tires were there in the first place and if the speedometer was accurate at that time. An easy way to find out how inaccurate his speedometer is, is to get on a major highway and drive 10 miles per the mile markers, (they are very accurately placed). Note the mileage at the start and note the indicated mileage at the 10 mile point. The advantage of this over driving one mile at 60 mph is that you don't have to drive at any particular speed and the distance will give a more accurate number. You could drive it at 10 MPH, 95 MPH or any variation of speeds and it will give you an accurate number.
So for ex. if you go 10 miles per the mile markers and your Odometer said you went 9, your reading 10% low. With that information in hand you fill up, noting how many miles your odometer said you went since the last fill up, lets say it said 280 miles, 10% of 280 is 28 miles, add that to the the indicated miles to get 308 miles traveled. Or apply it to the last MPG calculation of sat 10 MPG and WALLA, you are getting 11 MPG. Or add 10% to the indicated speedometer indication, did he ever get a ticket for speeding when his speedometer said he was OK?

Also from that information you can decide what speedo gear. Ford speedo gears change the reading approximately 7% per tooth added or subtracted. Reducing the tooth count increased the indicted speed approximately 7%

An alternative would be to use a GPS then you can check it any where and at multiple indicated speeds and it will be telling you exactly what you are doing without any personal involvement in the calculation.

Hope that helps you,

>-

Just as a point of trivia, factory speedos are acknowledged to be inaccurate to begin with. Your stock speedo can be off by + or - 10% right off the assembly line, a point that attorneys hired to defend against speeding tickets always make and also the reason why every cruiser out there has a *calibrated & certified* speedo, it's printed right there on the speedo face (I know, I know it's hard to read it from the back seat but trust me it's there) It's also an easy way to spot former cruisers because the certified calibration speedos only come with the Police Package & those are only available to municipalities.

 

[WPW Bronco]

For a young guy such as yourself, I think you'd be better to stick with 33's or smaller, especially if YOU are worried about you rolling it. The speed difference is going to be negligible as long as you drive the speed limit. Just be ready for the 10-12 mpg fuel consumption, a bit less than that Dakota gave you. But all in all, every bit of it is worth the freedom a FSB will bring you!

 

[bryan thomas]

For a young guy such as yourself, I think you'd be better to stick with 33's or smaller, especially if YOU are worried about you rolling it. The speed difference is going to be negligible as long as you drive the speed limit. Just be ready for the 10-12 mpg fuel consumption, a bit less than that Dakota gave you. But all in all, every bit of it is worth the freedom a FSB will bring you!

I own a 95 FSB and I run 32x11.50r15 bfg all terrains on my factory xlt wheels (15x7.5) with no problems. I've seen a guy w a 96 running mt 33x12.50r15 on mt 15x10s and he had to sawzall his bumper and then he crinkled his fenders when his body met tire while mudding. I'd stay with the 32's for now. My mileage dropped a little and my speedo is only about 2 mph off.

I'm going to upgrade to the 15x10 when I have more money. Bidi runs the same set up. I had an 87 for my first truck and never rolled it and I did some really dumb stuff so don't be to concerned about it. just don't take on any dukes of hazzard jumps or corners thinking that big tank is a drift racer and you'll be fine.

ANd to quote you a price on your truck w 6" and wheels and tires. I took mine to a 4x4 shop and he told me around $5000 for a BDS lift with all the other options. No blocks also. I believe it was Nitto Grapplers 36x15.50r15 (i think it was Nitto) MT bead lock 15x12's (5 tires and wheels) longer brake lines and some other things to make my lift totally finished. But that's what you can look to spend approximately. I'm waiting to pay off my truck before I go and do that. Good luck.

 

[brandcole73]

I have put 32s on both a 78 and a 96 with no lift. I had to cut a half inch off the rubber valance on the 96 so they wouldn't rub when turning. I wouldn't bother with the lift for these tires. I have a 78 with a 3 inch lift now with 35s. I don't remember the milage diffference on the other ones. I don't think the 96 changed more than a mile or two per gallon when I put the 32s on it. I used it for a daily driver and had to get snow tires for the winter though. The big wide tires would not stop the truck in wet snow!!!. I couldn't tell you what my 78 with the 35s gets, the odometer is not working. 400, headers, 4 barrel holley, It doesn't get much! I never got my spedos adjusted, I checked the 96 against my GPS and it read about 4 miles slow at 55 mph.

 

[bryan thomas]

I have put 32s on both a 78 and a 96 with no lift. I had to cut a half inch off the rubber valance on the 96 so they wouldn't rub when turning. I wouldn't bother with the lift for these tires. I have a 78 with a 3 inch lift now with 35s. I don't remember the milage diffference on the other ones. I don't think the 96 changed more than a mile or two per gallon when I put the 32s on it. I used it for a daily driver and had to get snow tires for the winter though. The big wide tires would not stop the truck in wet snow!!!. I couldn't tell you what my 78 with the 35s gets, the odometer is not working. 400, headers, 4 barrel holley, It doesn't get much! I never got my spedos adjusted, I checked the 96 against my GPS and it read about 4 miles slow at 55 mph.

I meant to say I just pulled off my front valance and sawzalled the rest of the rivets or whatever they were that didn't come off when I yanked it. It looks better and looks a bit taller now. I like it. And nothing rubs either at full lock.

 

[dsgb9840]

i have a 94 bronco, with a 6" kit and 35" bfg muds..........i get 7.5 mpg city /emoticons/[email protected] 2x" width="20" height="20" /> i used to get 10-12mpg and my speedometer is 5 mph slow..