question about mileage and the speedo gear?

Alnobles · 07-23-2006, 08:42 PM

Does the speedo gear affect the odometer? This might be a stupid question but I reallly have no idea.

**BigWaylon** · 07-23-2006, 08:56 PM

Quote:

Originally Posted by Alnobles

Does the speedo gear affect the odometer? This might be a stupid question but I reallly have no idea.

yes...directly related...

Greg

daveg13 · 07-23-2006, 09:08 PM

Yes, if your not reading the correct speed, your odo is off.

**cheesycook** · 07-23-2006, 09:34 PM

And not running the right speedo does affect the way your motor performs.

Alnobles · 07-23-2006, 09:49 PM

Quote:

Originally Posted by cheesycook

And not running the right speedo does affect the way your motor performs.

The milage seems to be going up faster than the miles that I'm driving. The guy I bought the jeep from never changed the speedo gear and the total mileage on it seems much higher than it should be for the way it runs. I'm thinking it may be like 20,000 miles off. I know it should be getting better than 15mph on the highway, even for a 6cylinder so I started thinking it was because he never changed the speedo gear. Thanks for the responses.

adam728 · 07-23-2006, 10:24 PM

Bigger tires + stock speedo gear = odometer shows LESS miles than actually traveled, not more.

How well it runs is hardly an indicator of mileage. My 85 Toyota ran great with 203,000 miles on the ticker. My 89 Toyota (same engine and tranny) bit the dust at 146,00 miles, and was dying long before that.

Alnobles · 07-23-2006, 11:18 PM

Quote:

Originally Posted by adam728

Bigger tires + stock speedo gear = odometer shows LESS miles than actually traveled, not more.

How well it runs is hardly an indicator of mileage. My 85 Toyota ran great with 203,000 miles on the ticker. My 89 Toyota (same engine and tranny) bit the dust at 146,00 miles, and was dying long before that.

Yeah, I'm having trouble doing the math. I always get it backwards. Maybe the mileage is just that bad!

adam728 · 07-24-2006, 07:02 AM

No, since the odometer will show less miles than actually traveled it will come out that it is showing you worse mileage than you are actually getting.

Say you drive 150 miles on 10 gallons of gas, 15 mpg. With 10% larger tires and a stock speedo gear you'll show only 135 miles and be calculating 13.5 mpg.

**BigWaylon** · 07-24-2006, 07:23 AM

Quote:

Originally Posted by Alnobles

I know it should be getting better than 15mph on the highway...

I would hope so...

Greg

Rule303 · 07-24-2006, 07:52 AM

Get the right speedometer gear. Its a $15 and five minute fix.

**cheesycook** · 07-24-2006, 09:53 AM

HERE is the chart and a quick "How to".

buddastrat · 07-24-2006, 11:19 AM

It seems jeep always sets them to rack up miles faster. Maybe to get out of warranty quicker?

My first two TJ's were off. I had the 30" tire group and when I put on 31"s it came out perfect. That's without changing the speedo gear.

I read the six speed tranny rubi's are dead on. That would surprise if it's true. Anyone know?

msalyer1956 · 07-24-2006, 11:27 AM

My stock Tj I bought a couple weeks ago shows 60 mph when I am traveling 58 on a gps. Stock 27" tires. I am going to go to 30x9.50's in the spring and it will probably be close to right on then.

BLACK05X · 07-24-2006, 02:00 PM

i have the six speed on the stock 28 inch tires. I will be moving up to 31's do you think it would be dead on or would i have to change it.

burchey · 07-24-2006, 02:18 PM

I've thought about this too. Is the "Rubicon speedo/odometer is set up for 33s even though it comes with 31s" rumor true? I think that doesn't make any sense, but I've read it several times on this board.

07-23-2006, 09:34 PM	#4
cheesycook Accident Prone Bonehead Join Date: Apr 2003 Location: Hermiston, OR Posts: 2,659 Profile Gallery Classifieds My Jeeps	And not running the right speedo does affect the way your motor performs. __________________ 98 TJ 4.0 Stick 30 Lock-Right/44 True-Track,4.56. Fire RED. Optima Red top. 3" Full Traction lift, Cragar 352 Street locks w/3.75 BS. 32" BFG AT's. Sailcloth top. Classic4x4 tubular fenders. AtoZ Fab rockers and front and rear bumpers. TBT sportsbar and rear spreader. VDP 6 speaker bar. 2K Intake Manifold. Tuffy Speaker lock boxes. Power inverter. Cobra CB. Magellan GPS. Bed lined tub. 3core HD radiator. Olds airbox with Hummer snokle. Besttop seat covers with heaters. All running lights LED.Steering and oil pan skids. Mile Marker PE8000 winch. Currie Anti-Rock. Olympic trunk. Tuffy Console....and Buddha on the winch. :) And a child seat stained with mud. Hermiston, ORL AtoZ Where Zach makes me toys! Stu-Offroad, because I don't have a clue, but Stu does!

07-24-2006, 09:53 AM	#11
cheesycook Accident Prone Bonehead Join Date: Apr 2003 Location: Hermiston, OR Posts: 2,659 Profile Gallery Classifieds My Jeeps	HERE is the chart and a quick "How to". __________________ 98 TJ 4.0 Stick 30 Lock-Right/44 True-Track,4.56. Fire RED. Optima Red top. 3" Full Traction lift, Cragar 352 Street locks w/3.75 BS. 32" BFG AT's. Sailcloth top. Classic4x4 tubular fenders. AtoZ Fab rockers and front and rear bumpers. TBT sportsbar and rear spreader. VDP 6 speaker bar. 2K Intake Manifold. Tuffy Speaker lock boxes. Power inverter. Cobra CB. Magellan GPS. Bed lined tub. 3core HD radiator. Olds airbox with Hummer snokle. Besttop seat covers with heaters. All running lights LED.Steering and oil pan skids. Mile Marker PE8000 winch. Currie Anti-Rock. Olympic trunk. Tuffy Console....and Buddha on the winch. :) And a child seat stained with mud. Hermiston, ORL AtoZ Where Zach makes me toys! Stu-Offroad, because I don't have a clue, but Stu does!

07-24-2006, 02:00 PM	#14
BLACK05X Registered User Join Date: Oct 2005 Location: Long Island, NY Posts: 74 Profile Gallery Classifieds My Jeeps	i have the six speed on the stock 28 inch tires. I will be moving up to 31's do you think it would be dead on or would i have to change it. __________________ [COLOR=Black][B] 2005 Black Wrangler X [/B] [/COLOR] [COLOR=Black][B]4.0 Liter 6 speed[/B][/COLOR]

07-24-2006, 02:18 PM	#15
burchey Registered User Join Date: May 2006 Location: San Diego Posts: 63 Profile Gallery Classifieds My Jeeps	Rubicons I've thought about this too. Is the "Rubicon speedo/odometer is set up for 33s even though it comes with 31s" rumor true? I think that doesn't make any sense, but I've read it several times on this board. __________________ [URL="http://myspace-886.vo.llnwd.net/01321/68/83/1321903886_l.jpg"]A tribute to my stolen jeep, may she rest in peace (and not pieces)[/URL]