Thinking of buying 6.4
 

Looking at buying a 6.4. Looking at a 08 f450 and 09 f350. The f450 has 94000 and is lariat loaded up etc. the 09 is a xlt with 139k. The f450 is slightly cheaper plus I like it better. But how much worse is the mileage on the f450 than the f350. I am going to be replacing the 2005 6.0 I have unless I decide to keep,it as my daily driver since it's paid for. Any major issues with the 6.4 that I should be looking for? Any changes from the 2008 to the 2009 trucks?

there are three job runs for 08. What does the door cert indicate for the manufactor date?

Remember the 450 most likely will have the 4.88 gears. check the door for that as well.

In the tech folder is a link for the window stickers. Get the vin and see what they have as a comparison.

The 450 will get worse fuel mileage with the 4.88's but will pull the heavier loads a lot better.

I'd expect to loose a mile or so per gallon.

Check the maintance over on both. Each should probably have had a coolant flush by now as well as transfer case and rear diff changes. The F350 should have also had the front diff changed by now too.

Look over the radiator seams, especially the drivers side for leaks at the plastic. the leak there.

The window sticker for the f450 says it has the 4.30 gears

4.30 is certainly enough for the heaviest of the loads.

That's what my thought was too. I will only be pulling a horse trailer that weighs in at around 11000 fully loaded regularly. Occasionally I will pull other stuff heavier than that but we're only talking a couple times a year. I feel either truck is more than capable of pulling my horse trailer. I like the f450 a lot better but have a little concern it's way over kill and the the mileage is going to be under 10 everyday. I would like to get 13-15 out of whichever one I were to get on an everyday vehicle. I most likely will do the deletes at some point.

My life time mileage on my F250 4x4 with 3.73 gears was 11.5.

Out of 86K most of it was heavy towing. (14-15K). Lots of car towing and almost all of my driving is hwy or interstate for the most part.

As a commuter I would not use this truck. But as a hauler yes.

You would not use a 6.4 or the f450? I get about 13-15 with my 6.0 and have done the same with all the 7.3 powerstroke I have had. A single rear wheel 6.4 would that do about the same or is the 11 pretty much all I should expect. I know I have heard the 6.4 is hard on fuel.

I would expect 11-12 on average.

Unloaded I could get 13 around town and 16 on the hwy with mine.

How much better does your 6.7 get? How's it pull compared to your 6.4.

Towing mpg is the same. About 8 to 10.
Exhaust braking on the 6.4 is better. Trans is smoother too.
Unloaded mpg is better in the 6
7.

Have both trucks kept the dpf?

Yes, I didn't touch the emission in either one. I'd still have the 6.4 but I needed the drw to help with the wife's back.

6.7 runs really good and I am glad I made the purchase but there was nothing wrong with my 6.4 either.

Ok the 2009 I was mistaken it only has 78000 miles on it. Its a crew long box srw. It has the 3.55 ratio. Is this going to be bad for pulling our horse trailer? What issues do the 6.4's usually have. Head gaskets, egr etc? Any of them? Thanks for your help.

That 09 then is the one I would be targeting.

Head gaskets and EGR/EGR coolers are not problematic like the 6.0. You can even tune a 6.4 and get away with it. Caveat though is to tow in stock power levels.

Issues are coolant level and maintance. Take some test strips with you and check the nitrites in the coolant. I will attach a document that should provide enough info on the why.

You still want to ensure 5K oil changes and 10K on average fuel filter changes. Motorcraft filters only. If the oil filter cap on the motor is not the OEM then I would move on. It would mean he is using aftermarket filters which don't fit correctly.

Radiator seams since the tubes are now plastic. they will leak someones on the drivers side. I have the same radiator on my truck so ford still has failures. Check it. There is aftermarket options though.

the radiator will not fail on you going down the road so even if it develops a leak, as long as you keep the degas full then you are ok.

Ok thanks for the info. Should I be looking for the 3.73 gear or 3.55? Was itvonly the 2008 model year that has the 3.73?

You could get 3.73's for 09, but primarily they switch to the 3.55 for better fuel economy.

3.55 would be better if you are going to be using it for travel to and from work.

I like 3.73 gearing as the best all round ratio for my purposes.

Just bought an '09 F350 DRW 6.4 myself. Thanks for this info. Good stuff!

Not too long ago somebody posted a nice detailed narative of what to look for and to look out for on the 6.4 trucks...I have a friend now looking to buy one also. Where can I find that post for him to read? can it be reposted in this thread?
Thanks for helping find it.