BajaNomad

Dropping Air Pressure for dirt roads

John Harper - 3-21-2017 at 03:59 PM

So, I have read that it helps even on dirt roads to decrease air pressure somewhat. I'm taking my 2WD Ford Ranger to Mike's Sky Ranch in a few weeks. I have 235/75-15R tires currently at 35 psi all around. Should I drop to maybe 20-25 for the dirt road in? I've read it's easier on the ride and the suspension. I do have a high quality inflator/compressor to air back up before highway use on return.

Not a big offroader, but I do drive lots of dirt roads to trailheads in the Sierra (Chalk Bluff Road in the Tableland area too, washboard hell) in the summer . I was thinking it would be helpful there on long drives as well.

It's 20 miles to MSR, so I was hoping it would help? I don't want to beat up my truck if I can do something to help smooth the ride.

Any advice is appreciated. I have a good jack, rope, recovery straps, tire plugs, slime, jumper cables, siphon pump on board already. Also the compressor pump, and full tool kit as well as good mechanic skills.

John









[Edited on 3-21-2017 by John Harper]

Tires

yumawill - 3-21-2017 at 04:21 PM

New tires are perfect. Baja roads love to eat new rubber. Anyway I digress. The late Great General Patton discovered that a 30% reduction in tire air pressure greatly increased a vehicles ability to drive in deep sand. They were training at the Imperial Sand Dunes for the invasion of North Africa. I'm glad he did this homework for me. There's a company that sells tire deflators that will release air until a set pressure is reached and then no more. I have a set of four preset at 19psi. Nice tool. Good luck.

John Harper - 3-21-2017 at 04:26 PM

Anything Patton did is fine with me. I recall driving to the tip and also Abreojos back in August 1984 in my 1971 VW van and miraculously never had a flat tire. Only the saltwater lagoon and the crappy gas was a source of problems. Don't set your parking brake if you just crossed the lagoon at Abreojos and let it sit for 5 days. Very hard to move after that. And the bad gas made it very hard to start in the morning.

I did have all the balljoints done and the shocks (KYB GAJ) are relatively new. I take real good care of my truck, they don't make them anymore. I got 9000 miles on the tires, so not quite new.

John



[Edited on 3-21-2017 by John Harper]

Tomas Tierra - 3-21-2017 at 04:54 PM

Even just to twenty five psi will make a big difference.. It's about a one beer stop to air down:biggrin:

David K - 3-21-2017 at 04:59 PM

YES!
35 psi is street pressure.
When you are not on a street anymore, for any period of time, drop the pressure.
1) Puncture resistance: You will have fewer flats if the rubber can give as it goes over sharp rocks.
2) Increased traction: You can climb easier if the rubber can conform to the terrain (grab).
3) Increased flotation: You won't so easily sink into sand with wider print.
4) Smoother ride: The tires do more shock absorbing if they are not rock hard.

On my recent three Baja Expeditions, my normally 34 psi tires were deflated to 22 psi off the pavement. I had no flats, no stucks, and my back doesn't hurt.

In deep sand, I run them about 18 psi. I did not deflate for the 23 miles of unpaved Hwy. 5, as I did on a previous trip, or my short trips two weeks ago out from El Rosario. All my other off pavement trips were much longer runs. I have 4WD and traction control systems. If you don't, then deflate, for sure! If you get stuck, then let out more air!

BigBearRider - 3-21-2017 at 05:02 PM

What tires do you have? I've punished my BFG All Terrains, and never aired them down.

bajatrailrider - 3-21-2017 at 05:10 PM

On all my light off road trucks 18psi. Yo dont need air down on easy way to Mikes , but your truck will like it.

AKgringo - 3-21-2017 at 05:28 PM

What kind of load are you carrying? My Kia only weighs about 3600 pounds loaded for Baja. I have 225/75/15 tires that are properly inflated at 26 psi on the highway. I will drop to about half that in the deep sand, and around 18 lbs on the long backroad drives.

With the truck loaded the way you intend to travel, do a chalk line test across the tread to see if it wears off evenly when you dive in a straight line.

mtgoat666 - 3-21-2017 at 05:47 PM

For the occasional trip down a easy unpaved road, I never air down.
I only air down if the road is really bad and I need traction.
The problem with airing down is it takes time and energy to air up afterwards.
Entering makes sky ranch, I would not bother changing air. It's a fine road.

Some on here are full of hot air about air. They will change their air pressure 5 times per day. They just like messing around with their toys.

willardguy - 3-21-2017 at 05:58 PM

Quote: Originally posted by Tomas Tierra  
Even just to twenty five psi will make a big difference.. It's about a one beer stop to air down:biggrin:


one beer per tire Tom......hey no problem with the 1st.

Bajazly - 3-21-2017 at 06:05 PM

I usually go to about 20ish the first dirt I hit of the trip and air back up when I get gas on the day I leave where ever I am to hit the border. All the up and down is very bothersome and time consuming.

John Harper - 3-21-2017 at 06:27 PM

Quote: Originally posted by mtgoat666  
For the occasional trip down a easy unpaved road, I never air down.
I only air down if the road is really bad and I need traction.
The problem with airing down is it takes time and energy to air up afterwards.
Entering makes sky ranch, I would not bother changing air. It's a fine road.

Some on here are full of hot air about air. They will change their air pressure 5 times per day. They just like messing around with their toys.


I've never really aired down, but the concept does have merit. My friend is a grit smoker, so she can smoke and have a beer while I air down to maybe 25 and try it out. I have a compressor that airs back up fast (allegedly) so I've prepared for this at least.

Loaded light, probably over prepared, but that's what OCD does for you.

John



[Edited on 3-22-2017 by John Harper]

woody with a view - 3-21-2017 at 07:14 PM

Don't forget to rotate the air in your tires yearly, or every other oil change.

DavidT - 3-21-2017 at 08:16 PM

Quote: Originally posted by woody with a view  
Don't forget to rotate the air in your tires yearly, or every other oil change.


I buy the package at Jiffy Lube that includes air rotation and muffler bearings.

Tomas Tierra - 3-21-2017 at 08:41 PM

Quote: Originally posted by DavidT  
Quote: Originally posted by woody with a view  
Don't forget to rotate the air in your tires yearly, or every other oil change.


I buy the package at Jiffy Lube that includes air rotation and muffler bearings.




Top up your blinker fluid at the same time

John Harper - 3-22-2017 at 05:49 AM

I fill my tires with helium, makes the truck just float over the road.:cool:

Thanks for all your sage advice, everyone!

John

TMW - 3-22-2017 at 09:17 AM

I've had to drop the tires to 10psi once to get out of the sand. We dropped a class 8 truck tires to 4psi because he broke an axle (one wheel drive now) and he almost finished the San Felipe 250 in 2003. Ended up getting stuck behind a buggy at the end of Matomi Wash near the Hwy.

norte - 3-22-2017 at 09:42 AM

Quote: Originally posted by yumawill  
New tires are perfect. Baja roads love to eat new rubber. Anyway I digress. The late Great General Patton discovered that a 30% reduction in tire air pressure greatly increased a vehicles ability to drive in deep sand. They were training at the Imperial Sand Dunes for the invasion of North Africa. I'm glad he did this homework for me. There's a company that sells tire deflators that will release air until a set pressure is reached and then no more. I have a set of four preset at 19psi. Nice tool. Good luck.


General Patton and at least one other on this forum.

pacificobob - 3-22-2017 at 10:19 AM

NEXT!...what motor oil works best in these tough conditions here in "the baja"???

John Harper - 3-22-2017 at 10:42 AM

Quote: Originally posted by pacificobob  
NEXT!...what motor oil works best in these tough conditions here in "the baja"???


I see a lot of oil debates on my Harley Davidson forums. Ad infinitum. Oil of Olay is rated the best.

John

Martyman - 3-22-2017 at 02:34 PM

Quote: Originally posted by John Harper  
Quote: Originally posted by pacificobob  
NEXT!...what motor oil works best in these tough conditions here in "the baja"???


I see a lot of oil debates on my Harley Davidson forums. Ad infinitum. Oil of Olay is rated the best.

John


I love Oil of an old lay. Use it all the time.

mtgoat666 - 3-22-2017 at 03:05 PM

Quote: Originally posted by woody with a view  
Don't forget to rotate the air in your tires yearly, or every other oil change.


Are you supposed to change the oil :?:

woody with a view - 3-22-2017 at 04:38 PM

Every 10k using synthetics.

John Harper - 3-22-2017 at 05:55 PM

Turtle oil was favored by Sportster Ironhead owners, but that's forbidden now. It replaced sperm whale oil. That's over too. Now we run dino oil or synthetics.

John

[Edited on 3-23-2017 by John Harper]

TMW - 3-22-2017 at 08:46 PM

If your tires don't wear unevenly why would you rotate them?

John Harper - 3-23-2017 at 05:46 AM

Quote: Originally posted by TMW  
If your tires don't wear unevenly why would you rotate them?
Your front tires do the turning and will actually wear differently than the rear. That's why they recommend you rotate front to rear to balance the wear and give longer life.

John

rts551 - 3-23-2017 at 06:59 AM

When I rotated the tires on my motorcycle, it looked kind of funny.

dizzyspots - 3-23-2017 at 07:10 AM

there is actually a technical way to "air down" based on your truck and its load, there isnt really an arbitrary number, here's the scoop...load the truck as you would travel, gear, etc.

Measure the sidewall height (from the ground to the rim edge)..divide by 4...drop the pressure until your sidewall height is 25% less...record this pressure...this will be youre predetermined safe pressure for airing down...i use the simple generic deflators (not preset)...cuz sometimes im empty and sometimes im loaded...one psi does not fit all circumstances

So lets say fully inflated sidewall height is 4"...reduce pressure until its 3"..voila that pressure is your new "go to" pressure

Remember to air UP before getting back on to a reg highway and highway speeds...

[Edited on 3-23-2017 by dizzyspots]

Udo - 3-23-2017 at 08:26 AM

Quote: Originally posted by woody with a view  
Every 10k using synthetics.


I also add a can of PRO BLEND, a friction reducer to the motor. I have been using it for over 20 years. A friend was using it and showed me by using an automotive stethoscope (the one with the long rod). We listened to my motor as it ran.
Then added a can of PRO BLEND. Just about 95% of all my engine noise went away when I listened the second time!!!


P.S. I apologize for Woody and myself for the hijack)

[Edited on 3-23-2017 by Udo]

pacificobob - 3-23-2017 at 08:54 AM

i used to be skeptic where automotive additives are concerned. and many products are snake-oil and well deserving of that. however some products work well. i now am a believer in fuel stabilizers,injector cleaners, and diesel fuel lube/cleaners. they make me feel good, and my machines work better. especially noticeable after long periods of storage.

David K - 3-23-2017 at 10:56 AM

So from deflating tires to engine fluids?

Okay, I can play too...

After being a die hard dino oil guy, and changing the oil under the recommended 5,000 miles (Average 4,000 for me), I switched to synthetic in my Tacoma, Castrol Edge and ran that for 8,000 miles and recently changed it, again with the Edge. The synthetic at 8,000 miles looked nice the way the dino looked at 4,000 in my Tacoma. I could safely run it to 10,000 miles (as I could dino to 5,000), but like the other service recommendations, it is far cheaper to change the oil more often than to have other engine problems.

I also dump a bottle of Techron in my gas tank every so often.

In measuring my fuel mileage, neither Techron or synthetic oil improved my gas mileage... always keep the air filter clean/ replaced. The differentials and transfer case oils are also synthetic (Mobil 1), and changed every 30,000 miles. The Tacoma is not an eco car, it is a reliable, strong truck. 15-17 mpg with rare trips 0f 18-20.5 mpg recorded. It has the 4.0 liter V-6 and runs on 87 octane gasoline.

John Harper - 3-23-2017 at 11:42 AM

Quote: Originally posted by pacificobob  
i used to be skeptic where automotive additives are concerned. and many products are snake-oil and well deserving of that. however some products work well. i now am a believer in fuel stabilizers,injector cleaners, and diesel fuel lube/cleaners. they make me feel good, and my machines work better. especially noticeable after long periods of storage.


I use Seafoam additive in my Sportster, since it can sit for a couple weeks at at time. Works great.

John

woody with a view - 3-23-2017 at 12:51 PM

I did a Blacstone Labs oil analysis at 10k and they told me there was plenty of life left in the oil and to go 12k. 10k is easy to remember on the ODO and comes around every 18 months or so on the Tundra.

dizzyspots - 3-24-2017 at 02:40 PM

Dittos on Blackstone Labs..we do our entire ambulance fleet..run hard and put away wet and asafely fo past 12K with good oil analysis. The customary 3-5k oil change deal on dino oil does nothing but lighten you wallet faster...

David K - 3-24-2017 at 02:47 PM

Quote: Originally posted by woody with a view  
I did a Blacstone Labs oil analysis at 10k and they told me there was plenty of life left in the oil and to go 12k. 10k is easy to remember on the ODO and comes around every 18 months or so on the Tundra.


Dino or Synthetic?

PaulW - 3-24-2017 at 02:53 PM

Now days the vehicle tells you when to do service. The only modern car I have gets oil changes between 9 and 10k, and always with a new filter. Lots of talk on the Internet that says that is not good.
The previous car I had specified 10K between oil and filter change, but did not have the modern message to tell you that.
My Diesel F350 gets an oil change with filter every 20k miles. Been doing that for 170k miles.
All the above used full synthetic oil per manufacturers specs.
Spoke to a car rental service guy and he said no oil changes. Just top them off when needed. I guess the next owner gets the result?

Pacifico - 3-26-2017 at 09:06 AM

Quote: Originally posted by Udo  
Quote: Originally posted by woody with a view  
Every 10k using synthetics.


I also add a can of PRO BLEND, a friction reducer to the motor. I have been using it for over 20 years. A friend was using it and showed me by using an automotive stethoscope (the one with the long rod). We listened to my motor as it ran.
Then added a can of PRO BLEND. Just about 95% of all my engine noise went away when I listened the second time!!!


P.S. I apologize for Woody and myself for the hijack)

[Edited on 3-23-2017 by Udo]


Udo, Is this the stuff?

https://pro-blend.com/products/racing-engine-concentrate?var...

woody with a view - 3-27-2017 at 01:47 PM

Quote: Originally posted by David K  
Quote: Originally posted by woody with a view  
I did a Blacstone Labs oil analysis at 10k and they told me there was plenty of life left in the oil and to go 12k. 10k is easy to remember on the ODO and comes around every 18 months or so on the Tundra.


Dino or Synthetic?


Same stuff you use Castrol Edge 5w-30.

David K - 3-27-2017 at 02:35 PM

Quote: Originally posted by woody with a view  
Quote: Originally posted by David K  
Quote: Originally posted by woody with a view  
I did a Blacstone Labs oil analysis at 10k and they told me there was plenty of life left in the oil and to go 12k. 10k is easy to remember on the ODO and comes around every 18 months or so on the Tundra.


Dino or Synthetic?


Same stuff you use Castrol Edge 5w-30.


OK perfect... It was my first synthetic oil run, the price wasn't bad for going double the miles (8,000) what I ran dino on (4,000). So, you think triple (12,000 miles) is ok? I may compromise and do it as you are, at 10,000 miles. If that's the only cost to keep our Toyotas running, it is sure a great deal.

PaulW - 3-27-2017 at 03:50 PM

Good move to switch to Full synthetic. Longer oil changes and less engine wear. Other properties are better than Dino oil. The good things are well documented if one searches web sites of reputable sources.
Tip: When choosing oil look for an ACEA rating. Turns out that API stopped testing for wear back when the primary anti wear agent was removed from oil used for gasoline engines. Meanwhile the European test method, ACEA, continued to certify the oils for wear. Just about any level of ACEA rating will be better than any API rating regarding wear.

woody with a view - 3-27-2017 at 04:35 PM

i get 7 qts and an oversized filter in every 18 months or so for around $50. 10k is a good number.