I had an '03 Express cargo van with the 6.0. Now I have a '07 Savanna cargo van with the 6.0. Changed the oil the other night and tried to use a leftover filter I had for the '03 and it wouldn't fit. The threading is different on the '07 and nobody seems to know why. I'd like to know why this changed. Was this to save some poor engineer's job that he needed something to do? There are other improvements to their lineup that could be changed.

i believe that is a pf 48 filter.06 would be a 46

As an engineer myself (and one who designs engines, no less), I really agree and have to wonder a lot of times what GM is thinking. That said, I can almost guarantee that the decision was NOT made in order to save some engineer's job. A lot of my coworkers fled Detroit (GM/Ford/Chrysler) because of just how many engineers they were firing! Believe me, Detroit has no interest in preserving engineers' jobs. That may be part of their problem...

I run into similar "WTF?!" items on my Suburban regularly. But then I have tremendous respect for other things they do. For example, the basic drivetrain and body of this truck is incredibly impressive. 204,000 miles and still got me up from Mississippi in absolutely terrible running condition. It amazes me the thing even ran given how much work it needed, much less made a 1300 mile trip going 85 the whole way! Then I go to change the timing chain and I wonder why 1) they couldn't design it so you could remove the timing cover easily without dropping the oil pan 2) why they put one of the oil cooler lines directly underneath about 6 of the oil pan bolts 3) why they used this crappy method of sealing the oil cooler lines that doesn't look to me like it would ever work.

To answer your question, though, a lot of decisions are not driven by engineers, but by managers and accountants (who should not be allowed to make engineering decisions). For example, it could have been determined that this new filter allowed them to save $1 per engine, and cost them $100,000 to implement. So, after 100,000 engines they've broken even, and if their projected sales volume is 150,000 engines, that saves the company $50,000.

Yeah, I know, it sounds dumb, and a lot of times it is. But that is where major OEMs have gotten to out of desperation to compete with foreigners, primarily Japan.

thats exactly how they look at it, a couple pennies here and there over 1 million cars, dont make since to you and me. But im not like most dont buy on price. If it cost them an extra dollar and cost me 4 thats still be ok if it meant reliability or servicibility.

That's the part that I don't get. When you figure all these cost savings, let's say they come out to about $500 per car. Well, in many cases I'd be more than willing to pay the extra $500 (or probably even $1000) to have those items that they cut or changed for cost savings. In a lot of cases, you'll never know the difference (oil filters being one... c'mon, other than not being able to use your old one does it really matter?). However one thing that really does bug me is the cheap plastic in the newer interiors. I personally find that my generation Suburban has an interior that has much nicer feel, fit and finish, and build quality. At 204k miles it still doesn't have squeaks or rattles. Meanwhile, a friend of mine has an '05 Suburban, and even brand new the thing never felt like it had a quality interior and it's always had squeaks and rattles. To me, a nice interior is worth quite a bit.

Ford can't do a good job, either. I test drove a 2000 Excursion with 83k miles... the interior on that felt to be in awful condition when compared to my Suburban. Plus that V10 is crap. My 2004 Dodge that I had when I sold it at 107k miles was still in great shape, as brand new. At 120k now with the new owner it's still great, and feels that way.

Obviously you guys have not worked on a Fords or Chryslers. You have a ligament complaint but Ford is 100X worst and Dodge is about 10X worst. Ford will change a single part 2-3times in one year. Imagine that! You go to change your oil and there is 3 filters listed for your exact truck! Crazy!

gm has plenty of mid year part changes I cant tell you how many time i have heard from the parts guy "well we gotta get the part number off the old one to find out if its first or second design." kinda sucks if a customer just wants an estimate on something and it has to be taken apart just to find a part #.

They all do this, doesn't matter who the manufacturer is. As to who's the worst about it, I can't speak to that as I've primarily worked on foreign cars in my life, especially Jaguars. Jaguar keeps the same part long past its "use by" date and keeps on selling it. :)

The sad part is, the general public isn't like you and I. They want a car and they see the price tag and look at competing price tags and they go with what they think is a better deal. They will probably never pop the hood for the life of the vehicle. That is what service departments are for.

These are the people buying vehicles and GM and others know it and they bank on it. It sucks for people like us, but for the rest of the public they don't care. They want a vehicle at a good price.

It's much like politics. Nothing is run off common sense! :D