Gas savers

[Bobby Bass]

On a postive note this string is for saving some gas so you can spend it on fishing instead. Last week I bought new tires for my truck and the installer told me to make sure I inflate them all the way. Seems I have been keeping my tires at 40lbs which I saw on the sidewalls. As he pointed out the 40lbs is for seating the tires on the rim. the proper inflate tire is 65lbs.... Here I have been running on 25 lbs. under inflate tires..65 seems like a lot to me so I did bring them up to 55 ( as high as my gage goes ) Anyone else notice this? of course cleaning out the tool box of things I did not need to carry around and lowering my speed on the freeway which was not hard to do with all the construction. Some numbers that I will throw out. You can improve milage by 2% for every 200lbs you lose. 6% for inflate tires. driving 55 instead of 70 gets you 15%

( that's a big one ) and up 20% for smooth starting and coasting instead of rubber burning starts and stops. Am thinking of removing my tailgate that is another saver. In MN you can not drive with your tailgate down ( was given a warning by a state trooper on that one ) seems if your tailgate is down your rear bumper is no longer in proper postion to protect you or someone who hits you.. Just some passing thoughts..Reading over this please note the 65lbs is for 16" truck tires, please check your own tires. the 200# weight savings computes to my wife and one lab or both labs and my pit bull. How you save 200# is up to you

[archer59]

I would bet after a couple of months of running the tire pressure at 65# you'll be needing new tires.

Nick

[hanson]

Bobby Bass-

Don't remove your tailgate. I know people argue both sides of this one but I understand you will NOT get better gas mileage with your gate down or removed. Trucks are aerodynamically designed with the tailgate up. Removing the gate significantly alters the airflow across the cab & bed.

This topic has been discussed here before and I thought I remember this was the conclusion that was reached.

[Valv]

I agree speed is the most effective way to increase mpg considerably.

I have a Dodge Diesel with a short (4.10) rearend. I usually drive at 70mph intertstate and I get 15mpg average, if I keep it below 2000rpm which is 62mph it can get over 20mpg....That's a lot of savings, and I am going to do it from now on.

[Valv]

Quote:

---

As he pointed out the 40lbs is for seating the tires on the rim. the proper inflate tire is 65lbs

---

I never heard of this, but I am no expert in this field.

Are we sure it is correct ?

Telling people to put 25lbs or more of air in their tires can be VERY VERY dangerous.

I am not criticizing you, I just would like somebody with knowledge confirm or not this issue.

[blakjack23]

I agree with Hanson, dont' remove your tailgate.

[Jeremy airjer W]

The Psi rating on the side of the tire is the maximum cold inflation and is labeled as maximum cold inflation. this is the absolute maximum air pressure that the tire should ever be inflated to. The only time it would be neccessary to inflate the tire to this psi is when hauling or towing a heavy load.

Most tires have a max cold psi rating of 44psi. Truck tires can have a max cold rating of 75psi or more.

Inflating your tires beyond this can cause the center tread to wear out prematurely not to mention increasing your braking distance and decreased traction

Somewhere on your vehicle you will find the Manufacturers recommended tire inflation. This is the tire pressure that the manufacturer recomends for optimal tire wear, comfort, traction, and economy. If your not sure what to set your tires at, 32psi is a good start. This is a generic standard that just about everyone in the automotive industry uses. The only time this shouldn't be used is if you have the heavier duty truck tires with the higher cold psi rating.

[Dan Thiem]

Great points Airjer! (As usuall) Most of the vehicle manufacturers have the recommendation in the drivers door jamb on a sticker.

Alot of people just go by what it says on the tire. You should go by what it says in the door jamb for the best performance for each specific vehicle.

[Gus]

Airjer and Dan, you guys snuck in posts while I was typing mine! O well, I'll leave it for people to read. Pretty much the same thing I was trying to say.

Tires should be inflated to what the placecard on your vehicle says. Max tire pressure listed on the tire is just for the tire, that has no bearing on what vehicle you put it on. It's just a max. If the vehicle isn't heavy enough for that tire/pressure combo, the tire will bulge out in the center causing high wear and you will in short order wear out the middle of your tires. The opposite effect can happen if you under inflate your tires. The inside and outside edges of the tire will wear. Not only that, but it probably won't ride quite right.

(quick story) One time after a service at the local garage, my truck was wandering all over the road. I could not get it to track straight and it just felt really strange. I checked the tire pressure, and the garage had set the pressure to the max on the tire. 65lb. Placecard on my truck says 32 or 34 (cant remember right now). Anyway, as soon as I deflated to the proper level the truck magically tracked straight as can be down the road.

I also had a buddy who ran his tires at max pressure on his 2500HD. 20,000 miles and his brand new tires were bald in the middle and looked ok on the outside edges. He blamed the tires, but I have the same brand and style on my truck and I'm now at 30,000 and they look barley broken in.

This is just what I have always been told by my Grandpa who ran a service station his entire life, and also a couple of my real experiences.

I do get 2 to 3 mpg better if I keep my foot out of it and drive the posted limits or just below.

[Bobby Bass]

Got any tire installers out there reading this? I am running at 50# as I do carry loads of rock in my truck but will reduce when my work season is done (landscaping) I knew 65 was to much..

[Jeremy airjer W]

Hey gus your story reminded me of one. As everybody "SHOULD KNOW" when the temps start to fall the pressure in your tires will start to fall. You can expect this to be up to 12psi or more. We always see alot of tire repairs in the late fall and early winter because of the this. Any way I had this Honda CRV, one early winter day, that the customer camplained that it was squirly. I took it for a test drive and sure enough it was a handfull to hold on to. kind of like it had for flat tires. got back to the shop and sure enough all for tires were at 12psi.

This also reminds me of another good tip. Your front tires will look like they are low on air if you compare them with the rear tires. the reason for this is the extra weight of the motor and transmission on the front tires. If you think you can add air and tell when the tire is inflated by looking at it your are wrong. get a tire gauge and use it. Just the other day I was checking a tire for repair. first thing I did was check the pressure, 122 psi. The customer said she just inflated it until it looked right!

[Valv]

Quote:

---

The Psi rating on the side of the tire is the maximum cold inflation and is labeled as maximum cold inflation. this is the absolute maximum air pressure that the tire should ever be inflated to.

---

That's what I always thought, and I am glad Airjer confirmed this, thanks.

The reason I feel it's dangerous is when you have a 35lbs max tire, you put 25lbs more = 60lbs, and the temp outside is 85deg, the air in the tire will expand and get such high pressure it will blow the tire.

Kinda like the Firestone deal on Ford Explorers few years back (renamed Exploders) only reversed.

[fish-n-geek]

Few things - 65lb is not high, if that's what your vehicle is supposed to be running at. My front tires are 65 while my rears are 80lb! I'm at 43,000 miles on these tires and am finally down to about 3/32 of tread. (I'm getting new tires this month). If you are running the stock size tires at the vehicle's intended pressure, you'll maximize the life of your tires along with improving your gas mileage.

Highway speed is definitely a help. I took two routes on a trip two weeks ago that is about 300 miles each way. The first leg was mostly 70mph and the return trip was more like 60mph. I got just under 16mpg on the first leg and just over 17mpg on the return trip. Definitely made a difference.

As for removing the tailgate - you're better off with a tonneau cover.

-rus-

[fish-n-geek]

One more thing to mention - if your tires are rated to a max psi of 35, but your vehicle says to inflate to 60, you are probably running the *wrong* tires on your vehicle.

-rus-

[Valv]

Quote:

---

Few things - 65lb is not high, if that's what your vehicle is supposed to be running at.

-rus-

---

fish-n-geek it doesn't matter. Read the post:

< The Psi rating on the side of the tire is the maximum cold inflation and is labeled as maximum cold inflation

It doesn't matter which tire or vehicle. If it's labeled 35 then max 35, if it's 50 max 50, and so on.

I have Load Range E tires on my dually rated 80psi max....that's the max I can inflate them if I want load capacity, I usually set rear at 60lbs as a good compromise, front at 65lbs.

If I mount Load Range A 35psi tires and try to inflate them at 80lbs....I will not have a face anymore, and probably not many parts of my head neither....

For better gas mileage you should find out what's the best rpm range on your vehicle where you have torque and hp.

As I said on my truck the "sweet spot" is 1800/2000 rpms, but I have a diesel with short rear end. Gas engines are different.

As a rule of thumb, the speed limit of 55mph is also one of the best mpg settings, but I know for many it's not possible to keep it that slow.

[Bobby Bass]

Should also note here that the label on your door frame about tire pressure is for the stock tires that come with the truck. Very few people if any replace their tires with the same "stock" tires that come with the truck. Most people upgrade when ordering or change brands and style when replacing. Most dealers will sell to their employees at a very steep discount the stock tires when upgrades are made. ( son worked for a dealer ) this was a simple post turning into a warm discussion...

[Jeremy airjer W]

You should see the look on peaoples faces when they blow a tire up. People don't realize how much pressure a hose at a service staion can have. I have personally witnessed 1 car tire and lots of bicycke tires. You wouldn't believe how loud they are when they go.

Two more things to help your fuel economy. One is to make sure your air filter is clean. The other is to stop driving around with your check engine light on. Vehicles with this light on can be using a backup mode of engine management wich can be far less economical since fuel and spark are determined by preset values rather than the actuall conditions.

[Ole1855]

Okay, I'm going to stir the pot a little bit.

I just looked at my tires and the sticker on the door, here's what they each said.

Tires; Max. cold PSI 50

Sticker; Front tires max. 50 PSI, Rear tires max. 80

So, who and what is right?? If I go by what I'm reading here, the rear should be inflated to 80 psi, but I also read here, that I should never inflate beyond tire max?!?!?!

[Jeremy airjer W]

Ole, what kind of vehicle and are they stock tires?

"YOU SHOULD NEVER INFLATE A TIRE BEYOND ITS MAX COLD TIRE INFLATION RATING"

[Ole1855]

2001 YukonXL 2500, the truck came with 245 75R 16, I stepped them up when I replaced them to 265 75R 16.

[Jeremy airjer W]

I would bet that the original tires where a load range E (i think its E)which is a heavier duty or higher load rated tire so to speak. The tires you replaced them with, I'm betting, are a LT tire (light truck) wich is not a heavy load rated tire. If you are not hauling around any suggnificant weight you might be O.K. If you are then you may wan't to talk to the folks you bought your tires from to see why they didn't replace or why they didn't tell you they didn't replace them with the higher load range unless they are not availeable in that size.

I would say that the pressure on the door sticker would inicate that you are indeed supposed to have a higher load rated tire to accomodate the higher hauling/towing capabilities that this vehicle has.

[Ole1855]

The originals were a load range E and so are the ones that I replaced them with, just a different brand and diameter.

[Jeremy airjer W]

are you shure it says "load range E" on the tire? or better yet does it say load range E on all the tires? I have seen seen where an LT will sneak on to a vehicle.

[Valv]

I am not sure 100% but I've never seen Load range E rated 50lbs, range D yes, but all the Es are 80lbs.

What brand of tire and model do you have ?

Edited again:

By the way wasn't this supposed to be a Gas Saver thread ?

[Ole1855]

Oops, my bad, they are actually load range C.

Now to get back to what Valv suggested. I haven't done this but a friend did and this is what he has told me. He bought the KN airfilter system and put it on his new Chevy pickup, I think he said it ran him about $350, he said he has picked up 3-4 mpg. This is second hand info. but the guy hasn't lied to me before.