Thanks for those who posted tire advice concerning my 2000 Dakota. I went back to the stock size in an all season passenger car tire but not without some difficulty.
At Wallyworld, I told the service writer the size. I had a copy of the list and so did she, and she turned to the truck tire page.
"I don't want truck tires (taking the advice here). I want passenger car tires."
"I'm not looking at truck tires (the page was captioned 'light truck and SUV') I'm looking at.... .... .... tire tires."
"Well the ones I want are on the first page. (Pointing on my copy to some Uniroyal AS tires). Turn the white walls in."
So after sorting that out, I looked at the authorization ticket and it said 5W30 for the oil change (apparently computer generated based on the vehicle info) and I said I wanted 10W30.
After maybe half an hour, I got paged to the service department where the following conversation occured with the mechanic.
"Do you know the size you've asked for isn't the same as what's on the truck?"
"Yea, but the size I've picked is the right size. Its what's on the sticker, same size as the spare. The previous owner put on oversize tires. Don't know why."
"OK. Just thought I'd better check. It did look like it was sitting a bit high". (Now, how high its sits is a real good method of determining the right size tires, don't you think?)
So I went and wandered back out into the store. Then I got paged again. Had this coversation with the service writer and manager.
Service writer
"We only have three of those tires."
Manager interjecting while passing through
"The computer says we have four, but one is mislabeled as a 75 when its really a 70. A 70 is shorter."
Me
"What else do you have?"
The service writer flipped to the LT/SUV page, indentifed some gypo brand WL tire in a P size but with an LT tread pattern and checked inventory on the computer. Looking over her shoulder, I saw inventory of "1", so I didn't have to argue that point with her (fortunately, after the earlier discrepancy, it didn't occur to her that computer inventory might be wrong on this one too!).
So she went back to page one and suggested a Goodyear something or other (silence on my part, remembering the advice here) and then went to the inventory screen... which fortunately for me showed 3 in stock, so I figured I was safe.
Service writer
"Let me call another store and see if I can get you a 4th tire. If they have one we'll go get it right away."
So it turned out the other store had enough to make a set of 4 on both the Uniroyal and the Goodyear.
Service writer
"They have both. Which do you want?"
Me (seems real obvious)
"My first choice."
OK. That's done, so I wandered back out into the store again, for a long time this time, and, wondering if this was all manipulation to get me to buy something before they'd cut my truck loose, found an Old Blue Eyes CD to give as a Christmas gift to a relative old enough to remember when Old Blue Eyes was a new and upcoming singer, plus Jo Dee Messina's Greatest Hits for me. (Fervent hope I'd done what was needed to get my truck finished.)
Finally, I was paged that the truck was ready.
Service writer
"The sticker on the oil cap says 5W30. Y'know, its best to use what they say. I know someone who used 10W40 and it gummed up her engine and ruined it."
At this point, I wasn't particularly upset, although I was 3 hours into the deal. After all, they did sell me what I wanted (except for the oil) and they made a good effort to get the tires I wanted (and most fortunately, did so quckly within the context of the capabilities of doing so.)
So overall I'm happy. After all, had I gone to a real tire store, when they found out one of the 4 75s on the computer was actually a mislabeled 70, those "professionals" would have tried to sell me a whole set of 70s based on the pitch that a wider tire puts more rubber on the road. Blessed are the true amatuers!