new to forum not to colorado...

[milehigh]

hey there hypoid recommended i check in over here. been living in colorado(denver) for about 3yrs now, had my 2000 XJ for about a year. i love this thing perfect for this area. just wish i got better gas milage with prices being where they are and all that and the fact that this is a DD. havent done any major mods to my jeep, just put on a set of BFG ATs 28's i think, shit id have to go measure to know for sure. but went with a set of black steelies, 8 inch wide, so had to lift it to clear. a whole 1" in the front and a 1.5" in the rear. trying to stay fairly stock for a few more years till i get another DD. this is used for snowboarding and camping on the back trails(although not what you guys would consider a real trail) my other ride is a 62 galaxie which is a weekend cruiser and gets a whole 8-10 miles to a gallon. with the XJ though i do plan on, here in the next few months, freeing up the exhaust and the intake to allow it to breath better and maybe if im lucky bump my gas milage up.

 

[jdxj]

:: :cheers: Welcome

 

[hugeorgan351]

welcome

 

[Hypoid]

Hey Robert, I got your PM. The world just got a whole lot smaller! LOL

The group here is really good for all things XJ. I think most the people here just can't leave stuff alone...including me. LOL

When we put some used 235/75 tires on we got nipped for a few MPG. I remember we took some bald 225s off, but I can't remember the aspect ratio. They may have been 225/70/15s. I ran #s through a calculator, was kinda surprised at how much difference the aspect ratio made.

Here is the calculator: http://www.victorylibrary.com/mopar/tire-calc.htm

Have fun, Mike

 

[milehigh]

wow that is a big difference. i put my numbers in there 235/75/15 and i was suprised that they were really close to 29" which again using the old tires info 225/70/15 was about inch and half shorter. guess that helps to explain the mpg drop. thanks for the link, never actually knew that that was how tire height was calculated. i always thought that the 75 was the size of the sidewall, which in a way is true, but is dependant on the tread width. learn something new everyday! and a :cheers: to everybody here!

 

[Stumpalump]

With the tire on the vehicle measure from the center of the hub to the ground and double it to get the actual running diameter.

 

[milehigh]

so is that formula above not right?

 

[Hypoid]

Right? Only in a perfect world. Tire sizes are nominal, you'll find noticeable differences between brands. The chart gives you a way to compare changes.

If you still have the old tires mounted up you could compare the old to new directly by installing and measuring.

 

[milehigh]

i figured that much but that other guy made it sounds as if that wasnt right. no the other tires arent still mounted. all well not a big deal.

 

[Hypoid]

Filled up tonight: 14.5 mpg. We ran a tank of injector cleaner also, coming up on the e-test...