Hi Guys,

I got the General Grabbers in size 255/70-16 and put in OME 751 springs, new OME HD shocks all around and spacers in the rear for my SLS. I have a few questions...

Is the reccomended tire pressure the same for oversized tires?

I haven't run through a full tank of gas yet, but it seems to be A LOT worse now.

I flushed the coolant last week, and Monday I blew the bleeder screw out. I got the new style upper hose and bled the system. I filled the coolant tank and now it's about an inch or more lower. Is this normal after a flush? Does it take a while for the coolant to remain level? I haven't noticed any leaks since I got the new hose, temp is normal and there is no coolant in the oil.

With all these changes to the truck I am probably being more attentive than before and noticing things that are probalbly fine.

Thanks for the replys!

 

Rebleed the coolant system when the engine is cold and make sure you fill the coolant all the way to the top of the coolant bottle.
What air pressure are you running?

 

It can take several cold-hot-cold cycles to fully bleed the cooling system. Just check it every morning until it stays full. Should only take 2 maybe 3 days. Anymore than that and you have a problem.
Yes oversized tires can reduce your mpg. More weight = less mpg. Shouldnt make a huge difference though.
As far as psi, tire size makes no difference. You can run what you were before.

 

I'm running 32 up front and 40 in the rear.

 

If you are happy with the handling and ride then you are good. A few more pounds in the steers will help mpg though.

 

The tire pressure can effect your MPG pretty badly. I was looking at those tires a couple of weeks ago and I beleive that they are only a 44psi rated tire so dont go over that but go as close to that as possible. Remember that the higher you pump them up the more stiff the ride is going to be so its really up to you (mpg vs comfort). I run 55psi on all four with BFG's in that same size but they are a 60psi rated tire. Works for me. Your mileage will go down with the new tires but it should only be in the 1mpg range. Hope that helps

 

I would run them up by 5#'s, front and rear, if you want to get any mileage out of the.

 

Starcraft - You're right, they are max 44 lbs. I am now running 40 in the front and 44 in the back. Hopefully this will make a difference.

 

Hey Humroot ........... Just as a side note, the increased height of your new springs will cause the truck to be less aerodynamic at highway speeds and will rob you of mileage as well.

Hope the air pressure gave you some miles back!!

 

Keep a eye on the tyres to much air and you will wear the centers of the tyers out.