What is the ratio?

ikos10 · 03-27-2007, 09:21 PM

I have been keeping up with some ongoing chats about axle ratios, and I began to wonder....

Does anybody know what the stock gear ratio is for the 1998 Mazda B3000 4x4? I ask because it get horrible mileage, and seems to be geared way to low.... I mean plenty of low end, and absolutely no top end. Been this way since we bought the truck. Now when we bought it, the rear had been lifted about three inches with some blocks and an aftermarket hitch. I assumed whoever had it before we did, even though it only had like twelve thou on the engine, used it for towing. Last fall I raised the front to match and changed the tires from 225/75/r15's to 33x12.50's on new rims. The advantage here is the speedometer seemed more accurate, but the mileage didn't change. I have been thinking since we got it that the gears were changed, So if anyone knows what the original ratio was, I could compare it to mine, and see if there is a difference.

75K30 · 03-27-2007, 09:48 PM

I believe the mazda came with two optional ratios. A 3.55:1, and a 3.73:1
How are you gonna determine the current ratio?

ikos10 · 03-28-2007, 06:51 PM

Okay, i am not sure how I was going to check that actually, for some reason I thought I could count the teeth, but after thinking about it all day, I remembered that the ratio is the differnce in turns the drive shaft makes vs the wheel..... right? Anyways, i am almost positive they are higher then 3.73, I mean if that were the case, and it were factory, would if affect my speedometer? I was under the impression that if you change gears to higher to run bigger tires, then it would at the same time correct the speedometer. Now if that is true, and it became more accurate with the 33's, wouldn't that mean that the gears are not factory?

Now with that said, how would I check what I have? Is there a way?

bradrhale · 03-29-2007, 11:03 AM

lower gears and bigger rubber makes the speedometer more accurate. count the teeth of the ring and divide that by the number of teeth on the pinion. that will give you an exact as you can not get exact by turning the tire and watching the driveshaft.

03-27-2007, 09:21 PM	#1
ikos10 Senior Member Join Date: Mar 2007 Location: york, PA Posts: 85	What is the ratio? I have been keeping up with some ongoing chats about axle ratios, and I began to wonder.... Does anybody know what the stock gear ratio is for the 1998 Mazda B3000 4x4? I ask because it get horrible mileage, and seems to be geared way to low.... I mean plenty of low end, and absolutely no top end. Been this way since we bought the truck. Now when we bought it, the rear had been lifted about three inches with some blocks and an aftermarket hitch. I assumed whoever had it before we did, even though it only had like twelve thou on the engine, used it for towing. Last fall I raised the front to match and changed the tires from 225/75/r15's to 33x12.50's on new rims. The advantage here is the speedometer seemed more accurate, but the mileage didn't change. I have been thinking since we got it that the gears were changed, So if anyone knows what the original ratio was, I could compare it to mine, and see if there is a difference.

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03-27-2007, 09:48 PM	#2
75K30 Senior Member Join Date: Jul 2006 Posts: 3,312	I believe the mazda came with two optional ratios. A 3.55:1, and a 3.73:1 How are you gonna determine the current ratio?

03-28-2007, 06:51 PM	#3
ikos10 Senior Member Join Date: Mar 2007 Location: york, PA Posts: 85	Okay, i am not sure how I was going to check that actually, for some reason I thought I could count the teeth, but after thinking about it all day, I remembered that the ratio is the differnce in turns the drive shaft makes vs the wheel..... right? Anyways, i am almost positive they are higher then 3.73, I mean if that were the case, and it were factory, would if affect my speedometer? I was under the impression that if you change gears to higher to run bigger tires, then it would at the same time correct the speedometer. Now if that is true, and it became more accurate with the 33's, wouldn't that mean that the gears are not factory? Now with that said, how would I check what I have? Is there a way?

03-29-2007, 11:03 AM	#4
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 9,558	lower gears and bigger rubber makes the speedometer more accurate. count the teeth of the ring and divide that by the number of teeth on the pinion. that will give you an exact as you can not get exact by turning the tire and watching the driveshaft.