that vintage vehicle with 3 speed trans used a lot of fuel on hwy due to the relatively high cruising rpm. It was created to carry and haul a load so was geared very low to begin with. Later vehicles had 4th gear overdrive to regain fuel mileage by lowering engine rpm. Larger tires lower engine rpm so the fuel saved by this will far outweigh the rolling resistance or tire weight differential we are talking here. Auto companys volume purchase smaller tires because they cost less to manufacture using less materials.
Switch back to OEM tire size?
- Thread starter otis24
- Start date
Odds are, your vehicle did come with LT tires and the 225/75/16 were just the cheapest tire package offered, not the one people wanted if there was no cost difference.
The 4.3L wasn't very strong for the vehicle size (though not weak for that era, except hauling a load) but as others mentioned your rear diff ratio can help or hurt you loaded or unloaded, whichever your greatest need may be, EXECPT we are not talking about much difference here, not like the consideration is huge mudder tires weighing twice as much and 20% larger diameter!
If you never haul a significant load, and don't care how it looks, or rides, or ground clearance, get the cheaper, normally smaller tire, but the average non-base-model variant of the K1500 probably came with the 245/75/16 from the factory, and some had 265/75/16 from the factory, though "IMO" that is pushing it for handling on a 6.5" rim.
Ultimately I'd get the 245 again. It is a pickup truck and that seems like it has more virtues than detriments.
The 4.3L wasn't very strong for the vehicle size (though not weak for that era, except hauling a load) but as others mentioned your rear diff ratio can help or hurt you loaded or unloaded, whichever your greatest need may be, EXECPT we are not talking about much difference here, not like the consideration is huge mudder tires weighing twice as much and 20% larger diameter!
If you never haul a significant load, and don't care how it looks, or rides, or ground clearance, get the cheaper, normally smaller tire, but the average non-base-model variant of the K1500 probably came with the 245/75/16 from the factory, and some had 265/75/16 from the factory, though "IMO" that is pushing it for handling on a 6.5" rim.
Ultimately I'd get the 245 again. It is a pickup truck and that seems like it has more virtues than detriments.
The truck is a beater, but it has to last. Odometer broke 4 years ago. Guessing that it has about 125k miles on the 4.3 V6 motor. I don't do much off-roading. I will probably stick with the 245s. Just because of availability and ride height. As it is, I can slide under the vehicle for repairs when needed. Any lower, that won't be the case.
Thats right. Larger tires will cost more at the gas pump over time. It would be an engineers dream to meet CAFE by simply slapping on taller tires, but it does not work that way. In fact, with stringent CAFE requirements to meet, they optimize MPG by specing the correct size from the beginning.
If money is an issue, get the size that’s less expensive, I would stay w 245
On a side note, the radar at the edge of town matches my speedometer when going 30MPH.
Thats good but its just a happy coincidence. It does not necessarily mean you have the optimal sized tires. My "high tech" Hondas speedo was off by 5-6% from the factory.
With a V6 under the hood and 4wd, I would definitley use stock size, but thats just me. You said you like fitting under the truck without ramps so you do whats best for you.
With a V6 under the hood and 4wd, I would definitley use stock size, but thats just me. You said you like fitting under the truck without ramps so you do whats best for you.
I’d probably stay with the 245-75 but if 245-70 is available would consider it for Oem diameter, depending on how the whole thing looks, basically. 70 series tires get soft for me in the handling department and 75 would be even moreso.
IF the original was an LT tire, I might me inclined to go all the way back to oem sized LT and see how it drives!
IF the original was an LT tire, I might me inclined to go all the way back to oem sized LT and see how it drives!
^ Really doesn't matter enough to consider with this small a size change difference, nor will fuel economy change much. It will seem like it changes more than it does, because the odometer is tracking fewer measured miles versus actual miles traveled per gallon of fuel with the little bit larger diameter tires.
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