Farm pickup and new tire mileage?

So I have a 2008 Dodge Ram that I use to haul hay and take my tractors to shows. Well the last load of hay was a hundred bales. So I was probably a little over weight but with it in the tow/haul mode I showed 17.5 to 18.5 mpg on the way down. Well the tires were the originals with almost 80,000 on them. I had new Toyo tires put on and now I only get 13.5 to 14 mpg unloaded without trailer. Could the tongue weight on the rear tires have cause the high mileage readings? How do these readings get generated? Does the computer only get a signal from the rear axle? My new tires are the same size but of course they have taller tread! Anybody else run into this?

I'm not sure how much taller your new tires are but the taller the tire makes them harder to turn. The taller tires have the leverage advantage that works against engine HP especially pulling a load. It's like breaking your lug nuts loose, the longer the handle on the tire tool the easier it is to turn the nuts. But if the lug nuts were trying to move the lug wrench it would be harder with the longer handle. Theoretically taller tires make less revolutions which can give better fuel mileage but when pulling a big load it's a disadvantage. Hope this makes sense.

I have a 2008 1500 and WIND makes a big difference, as much as you are saying yours varies!

I got less than 40,000 miles out of original tires! Wrangler HP's.

tread type can make a huge difference. an all season basically a mostly closed fine tread will pull easier than a very open aggressive tread which acts like a fan moving air and require more power

Well years ago I couldn't get over 30k out of a set of P275 whatever 16's Michelin radials. And that was what you could get as I tried several brands. Couldn't help remembering the Sears Roebuck commercials, back when radials first were officially introduced here in the US (and most of use know that saga as to why it took so long) where some guy got 60,000 out of his new then Sears Radials; Allstate I think, or who made them.

I'm currently running a set of GY whatever GS2s made here, or something like that, 20" on my P/U. Have 22k on them and looks like I will be hitting the wear marker at around 30. Seldom a load and seldom over 60 mph; 99% concrete or asphalt.

When radials first came out the tire dealers were whining about the long mileage one could get with them and what that would do to their bottom line. Well apparently somebody solved that riddle. But what do I know about it other than running and paying for them.

Mark

Sears used to have their "Guardsman" made by an overseas firm called Michelin. As for wear on today's tires Bought a new F-150 on 2001 took the OEM Firestones off at 88,000 miles and they were still legal, probably could of gotten another 5-8,000 miles out of them, but they were starting to act a little freaky in snow/slush (not that they were ever good in rain or slush). Put a set of Goodyear RT/S on it replaced them at about 60,000 miles, three were legal and fair, evidently I ran it with an under inflated tire and trashed one. Went back with the same Goodyears. Weight and road surface are big factors in tire wear and as I proved proper inflation. Proper inflation is also a factor with gas mileage. First trip I took in the pick up with the 2nd set of Goodyears my MPG was 2-2 1/2 MPG better than I had been doing, the folks that installed my new tires aired 'em up a little higher than I was running. Rolling resistance can also vary from tire model to model, factors are side wall stiffness and rubber hardness. I had a tire dealer explain to me some OEM tires don't last very long because the manufacturer traded gas mileage for tire longevity, they put a tire with lower expected life on but it improves the EPA gas mileage rating of the car.

Tire weight will affect mpg. So will tire size and tread pattern.

Did you have the same fuel source. I don't know about diesel but I can tell you there is a lot of difference in gasoline. Based on my MPG readout on my car traveling the same roads, I get roughly 2 MPG (consistently) difference between WalMart gas and a service station where I trade. You guess which is best. I routinely drive in north central Texas, all interstate driving MPG computer readout is 28-30. Last year when I went on vacation west NM and AZ, when I left the Dallas, Ft, Worth vicinity millage jumped to 32-33 MPG. as soon as I returned to Texas it dropped back to 28-30. I believe based on the above facts, that the percentage of ethanol is the factor. I drive full size car 6 cyl engine with an 8 speed xmission

No but TOYO tires are as good as it gets...

Wish I could get the life out of pickup tires that some of you guys are! I have never been able to get more than 20000 miles from a set of pickup truck tires. Doesn't seem to matter much what brand I run either. Gravel roads are hard on tires.

Count your blessings. I'm lucky to get 14 mpg pulling an empty trailer, 19 mpg with no trailer.

Your worn tires have to turn more times to go the same distance.

Effectively, making your speedometer show more miles to go from A to B than if you had new, deep-treaded tires.

That"s why they say old tires get you better fuel mileage, it"s BS, because you"re artificially showing more miles to go between the same points.

4 MPG, is quite a hit though.

What tires did you take off? Highway treads? Probably put a/t"s on it?

The guess-o-meter figures fuel use/mileage based on how long it"s holding the injectors open and speed/distance traveled. At least one new 1/2-ton diesel is actually showing a hair under what it"s actually getting, normally they are a bit optimistic.