I know there are other mpg treads but just wondering what are others getting for average mpg and what is your tire pressure?

I have a 3500 4x4 with BFG rugged trail TA and I run 50psi in it. I get around 16.5 - 17.5 mpg average. Since the summer months are here, I can imagine the tire pressure goes up a few psi equaling more mpg some people are seeing.

In my Nissan 240sx I noticed recently I was getting roughly 20mpg but the tire pressure was at 29psi (new tires set at the tire shop). I raised it up to 33psi but I haven’t calculated the increase in mpg yet but believe I raised up to at least 25mpg. Big change in mpg just with a few more psi.

What is the max psi you can safely run in these tires and not cause problems with the tire cupping or feathering?

 

You don't say if you have a dually or not. If you follow the Tire Guide that should be in the glove compartment, then it states 65psi front loaded and 75 rear loaded on the SRW SB. I believe the Dually states 70 psi in the rear.

As far as air pressure I have not seen any difference in mpg's with the lower psi. I do enjoy the ride better when the psi is lower, that's why DC states to do it that way when not loaded.

 

The BFG's (as with pretty much all after market tires) are rated at 50psi cold max.

 

sorry about that - my truck is SRW with an auto. Could I/should I run more psi in the BFG or as bigblue stated 50psi is about max cold for them and I don't want to go over that.

 

My BFG's are rated for 80psi (LR E's - not the D's that lots of folk buy as replacements); I normally run them 65 front and 60 rear for a slightly softer ride quality. Not sure it is any softer but it makes me think it is.

 

My stock BFGs can hold a max of 80PSI. When i'm running unloaded, I keep the back tires at 45PSI and the fronts at 55PSI.

This helps keep it from getting too tail happy on wet and slick roads.

Also, I've noticed no increase or decrease in MPG in relation to air pressure. The engines must not even feel the difference since they have so much torque. A gasser on the other hand is a different story.

 

Unloaded, which for me is most of the time, I run 70 front 60 rear, rotate every 5000 miles very even were, but I think I'l go to 60/50. I have the michelins.

 

I run mine at 55-60 front and 50 to 60 rear unloaded. Yes It does help the ride. Also as some have said make sure you rotate at least every 7.5k miles to ensure good even wear and long life. I rotate the spare in after I have them balanced, this way when and if I have to use the spare it will NOT be brand new and cause problems to the suspension. I curently have 27k on the truck and about 10/32 tire wear left. They should go another 25k miles before having to buy new tires. Yes I will have to buy 5 but that way if I change brands then I can get 5 that match

 

I run the stock Michelins which have a max of 80 psi. I set them up for less than half load and add the 10 psi that is needed for driving over 65 mph, so I end up with something like 70 psi up front and 60 psi to 65 psi in the rear. I have a canopy, some seats in the bed, bunch of stuff like tools, water, etc., and often end up with 3 to 5 people and a dog in the truck, so I prefer to set up for loads and speed that I'll often encounter. Tire stress is cumulative, and I prefer to minimize the chance of a blowout or handling problems over comfort. For increased traction I'll get different load range E tires.

Another reason for running a higher psi is that a lot of tire pumps seem to have problems filling tires to 70 psi, and I haven't found a decent protable pump yet.

 

Very intersting reading. I had the tires at 50lbs because I saw some post here in DTR and TDR that said they put their psi at 50.

I went to Safeway to fill up my tires and I think I broke their air compressor. After pumping up all tires to about 57 - 60 lbs the thing stop giving me air. I left before the service attendant came over to complain about trying to fill up my tires and not filling up with fuel (they didn't sell diesel!) Got home and proceeded to break my back pumping air into the rear tires using a hand pump. About 150 pumps later I got one tire up from 60 lbs to 67 and stopped there fearing the tire pump would burst. Did the same thing on the other rear tire - what a workout supprise I could still walk. The fronts was only shy a few psi to 60lbs so it wasn't to bad. So I have 60psi in front and 67psi in the rears.

We'll see how it goes mpg wise as I am heading up to tahoe for the weekend - and a quick trip to reno for the hot august nights car show!

 

I've tried various pressures on mine & found no noticeable difference in MPG.

I had been running mine at around 55PSI on all tires when empty - Was going to have a heavy load so was trying to increase that - I have a compressor in my garage...

Well I was running them up...got to 62PSI.....and it wouldnt seem to get any higher..my guage was supposed to read to 100PSI...Finally I gave up & tried another tire...same problem - get to 62 or so & no higher - Man is this my compressor that's the problem?? Finally I ran to the local auto parts store & purchased a $19 digital guage - good to 150PSI..

What did I find?Well I had 92PSI in one tire and 86 PSI in the other! my old guage would read 62 PSI no matter HOW much higher it was! That guage is now in the landfill...

ZS

 

A hand pump? That has to hurt! and hurt some more. You'll be paying for that for days! How high is the cost of air now where you are?
Nat

 

Yes my back was in shock for several days and I had to load firewood from tahoe (free wood) too.

Air is actually free in CA - just trying to find one that can go that high of psi without the gas attendant chasing me off the lot (because I did not purchase gas there - the distance I have to travel to get diesel - 10-15 miles! and then use their air hose) when I smoke their air compressor.

On my long trip to Tahoe and Reno then back (over 400 miles) my mpg did increase. It increased 1mpg on average - this is 95% hwy though compared to the same trip several weeks earlier(went from 50psi on the tires all around to 60psi in front and 67 in the back) but the feeling of the truck with higher psi is great! - much less sway empty and definitely when loaded too.

 

Everyone needs to remeber something important here...

You can only compare apples to apples here. Smae tire same size is the only far comparison of air pressure. Side wall stiffness and most important contact patch size have a big effect.

Not worrying about side wall stiffness and assuming the contact patch is the same in the length dimension, if tire A is twice as wide as tire B, it would only require 1/2 of the psi for a similar ride. 315's at 50 psi are more like 55-60 psi in the stock tire.

In other words...a 10" wide tire with 65 psi supporting 2250 lbs (about the weight of a front corner on our rigs) would require 3.5" length of contact patch.

If you keep the same contact patch length (which equates to similar ride) and switch to a 12" wide tire, it would only require 53.5 psi.

 

another thing to consider is your gauge. Buy a high quality brass-internals unit...like snapp on or blue point...whatever. I am sure there are better units available.

Pen type gauges are worthless .

I run 50 on all and rotate every 5k. Was running higher pressure and I noticed the rears were wearing faster in the center...so I changed. No difference in MPG noticed.

JKE