I have a K15 1979 4x4 and am going to be replacing the tires. Currently I have LT235/15's on the truck. I inheritted from my Father a couple of yeasr ago and did a full body re-build. The door decal show H78/15 as the tire size for the truck. Currently the speedo is reading about 10mph less than what my ground speed actually is. From what I can tell the speedo sending unit is the proper one and is working. The question is: What tire do I need to keep my current 16m/gal and possible get my speedo to read correctly. Thanks for your ideas. Steve
With so many tire sizes available, you should find a tire shop with a knowledgeable associate. They should be able to tell you which size tires will maintain the correct ride height based on the factory specs and width of the tire you want. If you want to keep your current set, the alternate would be to purchase an aftermarket electronic sending unit and speedometer. The latter would prevent any future problems with tire size changes and / or rear end ratio changes. Note: If your speedo is reading incorectly, your MPG is not correct either.
Thanks MarkyB. For some reason I hadn't thought about the fuel consumption being off as well. I'll look into the electronic speedo as a possible fix to the problem. Steve
