7.3 Ike Guantlet

[Bob Rosadini]

3 hours ago, Steve557 said:

I would think GM and Ram just don’t do the volume in big trucks/van’s to justify a big V8.

Well if GM really wants to be a factor with their new class 4, 5 and 6 JV trucks they better rethink that position.

[jpd80]

40 minutes ago, Bob Rosadini said:

Well if GM really wants to be a factor with their new class 4, 5 and 6 JV trucks they better rethink that position.

Their new 6.6 gasoline engine is barely passable in 2500 with just the 3.73 gears, the optics don't look good compared to the 7.3.

[Steve557]

1 hour ago, jpd80 said:

Their new 6.6 gasoline engine is barely passable in 2500 with just the 3.73 gears, the optics don't look good compared to the 7.3.

Along with the front suspension (how can they still think IFS is acceptable after getting blown out for thirty something years in HD market??), transmission, interior, and just look at it ?.

[Bob Rosadini]

1 hour ago, jpd80 said:

Their new 6.6 gasoline engine is barely passable in 2500 with just the 3.73 gears, the optics don't look good compared to the 7.3.

 For sure.  How about it Roadway-you have all the GM info-what would keep them from bringing back the big block the gave away to ...Power Systems???

[Steve557]

5 hours ago, blwnsmoke said:

 

6 years old this may and my 6.7 has had ZERO issues with anything dpf or emissions related.  If you consider 5 gallons of DEF every oil change a headache, then I guess yes.

 

When you sell, you get back just about every penny of that diesel option so although it does cost more upfront in regards to a payment, it doesnt cost much more in the long run.  Add to that the fun factor of HP/torque, I wouldn't go gas.

 

Maintenance is more costly with 6.7  or any modern Diesel. I’ve seen way too many threads of people stuck with 6.7 repair bills in the teens to be comfortable owning a new Diesel out of warranty. Unless your towing the “fun factor” is very minimal for the most part as 6.2 and 6.7 are pretty much dead on 0-60.

 

If you have the money to burn or tow heavy regularly go with the Diesel, but in the long run it has a much higher chance of costing a whole lot more compared to say a 6.2.

 

Looking for to getting getting into a 7.3 in next year or two, happy with my 6.2’s but still missing some of the low end torque that I was used to in the old 7.3’s before I (or should I say the EPA??) switched to gas. The nicest part was being able to move up to Lariat’s with all the money I saved over the old XLT Diesels I used to buy.

Edited February 3, 2020 by Steve557

[351cid]

Couple of comments from someone who has a lot of experience with both gas & diesel.

 

I'm a trucker. I have run all 48 plus the lower 6 of Canada for 30 years & have almost 3,000,000 miles logged  I appreciate diesel engines. I know their advantages & disadvantages  

 

I'm also heavily involved in the old car hobby. I have a 22' enclosed car trailer that's outfitted with quite a few "field tools". It's 4500 lbs empty. 

 

When I bought my '04 Super Duty, it was a no-brainer to choose the 6.8 V-10. I run my equipment as long as it's still financially viable to do so. Ford was in the middle of the 6.0 fiasco, so that was not something I was going to fight for 20 plus years. I tow my 8-9k lb trailer 12-15 times a year with trips as short as 10 miles or as long as 500.

 

I went with gas not only because of the 6.0 deal, but also because I only live 2 miles from where I work. That may have been a determining factor even if the old 7.3 was available. Short trips will kill diesel engines. 180k miles later, I have no regrets. I service it every 5k with 6 quarts Mobil 1 5W20 ($30 give or take) & a $4 Motorcraft filter. My buddy with a 7.3 diesel does his every 7500 miles with 15 quarts of 5W40 synthetic Rotella  ($90 +/-) plus a $12 filter. Service wise, advantage gas. Neither engine has required significant repairs, so as of yet, no comparison there. Neither truck will be sold, so resale is also not applicable. 

 

My truck was equipped exactly as I wanted it except it had 3.73 gears. I knew going in I'd swap gears. When the truck had 36k miles, I spent the $1k for the gears & swapped to 4.30s. Again, no regrets. I realize I'm comparing two different engine series here, but I only lost 1.5 mpg highway (staying @ 70 or below). I actually gained .5 mpg in city as long as I don't "play". Towing; I gained significant mileage. The 4.30's put the engine in it's sweet spot in 4th gear at 60 mph (about as fast as you should tow a loaded trailer with trailer tires since they are rated @ 65 mph). Throttle position has as much to do with fuel mileage as rpm does, imo.

 

All this being said: that 7.3 gasser is going to make quite a few people happy. Not everyone wants or needs the upkeep & expense of a diesel. I, for one, will look at that engine when my '04 gives up.

[351cid]

I will also add, the my 6.8 @ 3200 rpm is putting 1892 lb ft torque to the ground. The math is= 440 lb ft (small changes with tune & exhaust I feel added 20 - 25 lb ft, but I'm adding 15 to the factory rating of 425) x 4.30 = 1892.

 

My buddies 7.3 puts 1865 lb ft (500 x 3.73) down. They pull pretty even as the numbers suggest. His biggest advantage is 12 mpg loaded vs my 9 mpg.

[jpd80]

16 hours ago, Bob Rosadini said:

 For sure.  How about it Roadway-you have all the GM info-what would keep them from bringing back the big block the gave away to ...Power Systems???

That old Vortex 8100 was not fuel efficient and whatever faults the 6.8 V10 may have had, it basically consigned the Vortex to history.

If GM is thinking of a larger gas engine, it better be a a damned site better than the old BBC was..

 

[MGolden]

We havea total of  11 , f350 crew cab 8ft bed with 6.2L. There is a mix of 3.73 And 4.30 gears and they run heavy, occasionally towing. The only MAJOR difference driving them (3.73 vs 4.30) is accelerating from a stop with a heavy load. Minor differences are rpm while cruising and the different transmission gears on SPECIFIC hills/routes/ etc. I think the affect of rear ratio on the Ike test is way overblown. Sure, the chevy MIGHT have been in a different trans gear and optimum power/rpm with a 4.30 but i dont think anyone has put numbers behind it. Blindly saying a deeper rear gear helps is simply not true in the uphill test.

[7Mary3]

Just now, jpd80 said:

That old Vortex 8100 was not fuel efficient and whatever faults the 6.8 V10 may have had, it basically consigned the Vortex to history.

If GM is thinking of a larger gas engine, it better be a a damned site better than the old BBC was..

 

 

Neither one of those were exactly what I would call efficient!  The Big Block Chevy has been reincarnated as the PSI 8.8L, and seems to yet still have a future, while the 6.8L has now been made history by the new 7.3L.  Have to say that after a number of DECADES having BBC's in the fleet I can't fault their durability.  3 valve Tritons were a much different story, though the V-10's were certainly better as they did not have the failure-prone VVT cam phasers that the 5.3L had. 

 

 Still not sure what GM may have in the pipe regarding a larger gasoline V-8.          

[snooter]

Rear gear help gets the truck moving from standstill while load is hitched......uphill test is run 1 truck down hill at 75mph and 2 truck run at 35mph downhill....kinetic energy will highly favor the 1st truck...as usual i have zilch faith in these tests...rv guys are the real deal and only feedback i have ever trustes

[jpd80]

48 minutes ago, 7Mary3 said:

 

Neither one of those were exactly what I would call efficient!  The Big Block Chevy has been reincarnated as the PSI 8.8L, and seems to yet still have a future, while the 6.8L has now been made history by the new 7.3L.  Have to say that after a number of DECADES having BBC's in the fleet I can't fault their durability.  3 valve Tritons were a much different story, though the V-10's were certainly better as they did not have the failure-prone VVT cam phasers that the 5.3L had. 

 

 Still not sure what GM may have in the pipe regarding a larger gasoline V-8.          

I go back and forth on big gasoline and at its best while max towing will use roughly 30% more fuel than a diesel

but, if you're doing lots of miles towing and  down to say, 3 mpg then there's a ton of fuel savings to be had by going to a diesel.

At some point, it becomes uneconomical to pick gasoline over diesel, so finding that point is the key.....

[jpd80]

38 minutes ago, snooter said:

Rear gear help gets the truck moving from standstill while load is hitched......uphill test is run 1 truck down hill at 75mph and 2 truck run at 35mph downhill....kinetic energy will highly favor the 1st truck...as usual i have zilch faith in these tests...rv guys are the real deal and only feedback i have ever trustes

The thing that impresses is that at the limit, the 6.6 was out of breath half way up the  mountain, the 7.3 doing it in almost three minutes less.

That is way more than just extra hearing to get a load going from rest, the gaps in 6-speed gears kept dropping the 6.6 back under max torque

making it fall back and back all the way up the mountain, altitude did the rest robbing more power from an already compromised package.

 

On the flat at 70 mph, both packages are going to tow and perform similarly, its only when stretched that the Silverado feels the pinch

and most owners may never need to grill their trucks that hard anyway. I just can't see the 6.6 shaping up in Medium Duty without

some radical changes.

Edited February 4, 2020 by jpd80

[7Mary3]

Take a look at the horsepower and torque of a 1978 F-600 with a 361XD V-8, a very common gas powered medium duty truck back in the day and tell me the GM 6.6L won't work!  UPS does fine with the current GM 6.0L in their 21,000 GVW 'package cars'  It will be fine for up to class 5 medium duty.

 

Nonetheless GM really needs to offer the 10 speed Allison and 4.10 gears as an option for the 6.6L.

 

Regarding the TFL test, of course the 7.3L would best the 6.6L soundly, but I think I could have got the 6.6L up that hill a bit better keeping it in 3rd. or 4th. the whole way up.  TFL doesn't test that way, and I understand their position (test all the trucks in the same manner).  One thing I thought was interesting was the 7.3L Super Duty TFL originally tested had 3.73 gears in it, but when they did the Ike run all of a sudden they had a different 7.3L Super Duty with 4.30's in it!  What was that all about?      

Edited February 4, 2020 by 7Mary3

[jpd80]

27 minutes ago, 7Mary3 said:

Take a look at the horsepower and torque of a 1978 F-600 with a 361XD V-8, a very common gas powered medium duty truck back in the day and tell me the GM 6.6L won't work!  UPS does fine with the current GM 6.0L in their 21,000 GVW 'package cars'  It will be fine for up to class 5 medium duty.

 

Nonetheless GM really needs to offer the 10 speed Allison and 4.10 gears as an option for the 6.6L.

 

Regarding the TFL test, of course the 7.3L would best the 6.6L soundly, but I think I could have got the 6.6L up that hill a bit better keeping it in 3rd. or 4th. the whole way up.  TFL doesn't test that way, and I understand their position (test all the trucks in the same manner).  One thing I thought was interesting was the 7.3L Super Duty TFL originally tested had 3.73 gears in it, but when they did the Ike run all of a sudden they had a different 7.3L Super Duty with 4.30's in it!  What was that all about?      

They have promised to test both, max towing requires best gearing available, the 3.73s will pull the result back a bit but I bet it still trounces the 6.6 thanks to the 10R140’s smaller gear steps 

[snooter]

3 hours ago, jpd80 said:

The thing that impresses is that at the limit, the 6.6 was out of breath half way up the  mountain, the 7.3 doing it in almost three minutes less.

That is way more than just extra hearing to get a load going from rest, the gaps in 6-speed gears kept dropping the 6.6 back under max torque

making it fall back and back all the way up the mountain, altitude did the rest robbing more power from an already compromised package.

 

On the flat at 70 mph, both packages are going to tow and perform similarly, its only when stretched that the Silverado feels the pinch

and most owners may never need to grill their trucks that hard anyway. I just can't see the 6.6 shaping up in Medium Duty without

some radical changes.

No..it keep dropping gears to maintain the rpm...the ford should have easily won with 3od gears to maintain rpms...hence reason why the 10sp makes mucho sense in regards to eeking out as much mpg as possible...again, where test parameters exactly the same?...under exact same parameters the 7.3 still walks away easily with 10sp..this was an utter useless comparison by a long stretch...as bad as tesla pulling the f150 right up the mountain

Edited February 4, 2020 by snooter

[jpd80]

55 minutes ago, snooter said:

No..it keep dropping gears to maintain the rpm...the ford should have easily won with 3od gears to maintain rpms...hence reason why the 10sp makes mucho sense in regards to eeking out as much mpg as possible...again, where test parameters exactly the same?...under exact same parameters the 7.3 still walks away easily with 10sp..this was an utter useless comparison by a long stretch...as bad as tesla pulling the f150 right up the mountain

The 6.6 wouldn't downshift until the engine revs dropped down to around 3,000 or 3,500 which is well below max torque

A and everytime it did that the mph dropped, I heard 38 mph roughly half way up.

 

The three OD gears don't come into it with the 7.3 and ten speed, its the smaller steps between gears that allow

the 7.3 on the boil, I think it pretty much kept around 55 to  60 mph all the way up.

 

No the test trucks weren't the same but, Chebby only has 3.73 gears and a 6-speed auto,

Can't blame Ford for GM putting out a deficient truck.

[jpd80]

3 hours ago, 7Mary3 said:

Take a look at the horsepower and torque of a 1978 F-600 with a 361XD V-8, a very common gas powered medium duty truck back in the day and tell me the GM 6.6L won't work!  UPS does fine with the current GM 6.0L in their 21,000 GVW 'package cars'  It will be fine for up to class 5 medium duty.

 

Nonetheless GM really needs to offer the 10 speed Allison and 4.10 gears as an option for the 6.6L.

 

Regarding the TFL test, of course the 7.3L would best the 6.6L soundly, but I think I could have got the 6.6L up that hill a bit better keeping it in 3rd. or 4th. the whole way up.  TFL doesn't test that way, and I understand their position (test all the trucks in the same manner).  One thing I thought was interesting was the 7.3L Super Duty TFL originally tested had 3.73 gears in it, but when they did the Ike run all of a sudden they had a different 7.3L Super Duty with 4.30's in it!  What was that all about?      

I don't think you could better that by much, it lost a ton of momentum going up the hill because of the gear steps not being close enough

I get the feeling that particular engine needs 4.1s and the 10_speed auto to keep the thing in the rev range. That is a gruelling test and 

truthfully not indicative of 95% of most things expected by owners.

Edited February 4, 2020 by jpd80

[LongHaulTransport]

Any idea when these start showing up in RV's?