Went from the LT225x75-16 to wider LT235x75-16 Yokohamas a few years ago with the lower load rating. Sadly, the MPG suffered toooo much. The good thing was, fuel was $2.30/gal. In the past year, upgraded to BFGoodrich Commercial T/A LT225x75-16 load "E". Awesome for MPG and the max is 80psi for fill.

The entire issue with wider tires are more surface contact for road friction. On a lighter weight vehicle, this wouldn't be an issue. However, our elephants tip the scales against us for going with wider tires. Keeping to the LT225x75-16 size in load "D" still isn't enough for both MPG and handling. When I upped to the LT225x75-16 in load "E" I searched the web for input. Found a Chrysler TSB about better MPG using the load "E" for California use with fleet Ram Vans. In 2002-2003 for the Ram Van Cargo, the LT225x75-16 load "E" became standard equipment.

Seeing a x-sectional of a tire, the sidewall bulge hurts MPG. Going with a higher load rating stiffens up that side wall for better handling and MPG.

Last week I took my B2500 maxi van out for a 500+ mile round trip after upsizing the tires a couple of weeks ago. Earlier I was asking about moving from LT225x75-16 Load range E to LT245x75-16 Load range E tires. I took the plunge a few weeks ago and this was my first long freeway trip with the new tires on.

First I have to say that I only used a tank and a half of gas, and we all know that with these large vans wind direction and highway speed can certainly affect MPG's. I only traveled over two days, but both days were light wind days and I tried to keep it between 68-70 MPH where I do most of my traveling.

I believe I saw about a +0.5 MPG difference using odometer mileage. But when I factor in a 7% error in the mileage readings (I actually travelled about 7% further than the odometer recorded), the difference increases to about 1.4 MPG difference using the larger tires.

Now I also have to say that I did some of the things that Stev mentioned in his post about increasing MPG's, including new wheel bearing grease, new diff fluid, brake maintanence, and I increased the tire pressure to 65/70 frt/rear, so the tire size increase may not be the only factor in play here.

After all is said and done, I am glad that I have gone to the larger Goodyear Silent Armor LT tires, if only for an increase in braking/traction performance. I have great confidence traveling in the van now even though it is an '01 with 155K miles. I am looking forward to two longer trips in the fall and next winter where I will get a better idea of mileage over a much longer trip over many days. Thanks to all for their input in helping me make this decision.

Sounds sweet. Keep us posted on your MPG gains and those tires. The load "E" tires offer so much more handling improvement too.

Hey, did you get the long stem metal valve stems too? These are a must when going to a higher load tire that can use the higher PSI.

If you get the time, use a drill grinder wheel or a dremel grinder wheel and take down the raised walls on the MAP sensor side of the throttle barrels. Make sure to have a shop-vac running and sucking the filings away while doing this. Then polish the edge on each barrel for a smooth air flow in.

This will help with MPG and give a little Hp boost too. Do NOT take down the walls on the IAC side. The Ram Trucks can, but for the van's it's a no-no.

This mod is basically what a Fastman mod is without the boring of the barrel diameters. The goal is to save fuel and not to burn fuel here.

One thing that I didn't see mentioned at all was the computer, the computer is chipped for the best mileage (?) with the factory options, when you change the tire size you change the gear ratio, I know that the owners manual for my pickup states that you should not vary over one tire size without changing the gears in the differential. If you are really looking for good mileage I would look at a replacement chip from an aftermarket supplier that will increase torque, horsepower and mileage and are legal in all 50 states

If you are really looking for good mileage I would look at a replacement chip from an aftermarket supplier that will increase torque, horsepower and mileage and are legal in all 50 states.

I am ignorant of "chipping" a vehicle, but I would like to learn and possibly upgrade. Is there some specific way of getting something custom for a vehicle to increase the MPG? I always feel I have to point out that on my specific van, I have the heavier 3500 frame and a 4.10 rear end. This B2500 van version was made to be a work vehicle and not a hiway cruiser. I am trying to change that into a freeway cruiser where a 13MPG vehicle is going to break my bank on long trips. I have long debated with myself whether I should spend money for a newer more fuel efficient vehicle, or save lots of cash with a used van that I can load up and even sleep in and pay more at the pump to keep her on the road in lieu of larger vehicle payments. Well I have made my decision to stick with the older van. Now I just try to do what I can to give myself a possibility of small positive increments in MPG.

If you have any specific information on a chip upgrade I would like to hear them.

thx for the input...

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