7.5 verses 7.3 diesel - Diesel Forum

Tazzman · 03-14-2005, 04:04 PM

This might be a stupid question. I’m trying to sell my truck and when I checked the VIN number it says I have a 7.5 liter diesel and not a 7.3 diesel. So my question is what is the different between the 7.5 and the 7.3? Is the 7.5 better or worse? [img]/ubbthreads/images/graemlins/confused.gif[/img]

ThePunisher · 03-14-2005, 04:29 PM

I believe a 7.5 liter is a 460 gas engine

Mwheeler · 03-14-2005, 04:43 PM

I own a 7.5L (460) gasser F-250 and I have driven a 7.3L IDI F-250 about a year ago. From what I can tell the 460 has more power than the IDI and IDIT (drove one of those too a while back). The only true difference I can say is that the 7.3 gets a lot better mileage than the 460.

hesutton · 03-14-2005, 04:49 PM

7.5 is a 460 gasser. The big differences (aside from gas vs. disel) the mileage stinks with the 460, that and the 7.3 diesel will go many, many more miles before it needs to be rebuilt. Heck my dang 5.0 gasser only gets 10mpg on the highway. I cannot imagine the mileage of the 7.5. [img]/ubbthreads/images/graemlins/eek.gif[/img]

Heath

sbbamafan · 03-14-2005, 05:28 PM

This is not to compare the two engines. I think what you have just dicovered is (assuming you are not the original owner) that a previous owner changed the engine before you got it and did not disclose this to you. The good side is that you ended up with a much better engine than you would have had. I would think that this will provide a higher resale value (even though it is not original). I know I was bound and determined to find a diesel. If it was a gasser, I wouldn't even go look at it.

Dsl_Dog_Catcher · 03-14-2005, 05:53 PM

[ QUOTE ]
7.5 is a 460 gasser. The big differences (aside from gas vs. disel) the mileage stinks with the 460, that and the 7.3 diesel will go many, many more miles before it needs to be rebuilt. Heck my dang 5.0 gasser only gets 10mpg on the highway. I cannot imagine the mileage of the 7.5. [img]/ubbthreads/images/graemlins/eek.gif[/img]

Heath

[/ QUOTE ]

Yep,

Got an 85 with a 460 ga$$er punched .060 and she gets 8mpg runnin' empty or fully loaded! [img]/ubbthreads/images/graemlins/eek.gif[/img]

Ron

Tazzman · 03-14-2005, 07:45 PM

Thanks for the help. Yes, you are correct I'm not the original owner when I bought the truck it had 62000 miles on it now it's at 82450 and still runs good. It just has a strong diesel smell to it.

comp486 · 03-14-2005, 07:59 PM

The 89 f 250 excab with injected 460 would get 6 around town and 16 on the hiway, averaged out to about 9 [img]/ubbthreads/images/graemlins/eek.gif[/img]. thank god I sold it long ago. [img]/ubbthreads/images/graemlins/warmsmile.gif[/img]

Mike Lewis · 03-14-2005, 09:00 PM

My '91 F-150 with 302 got 7mph pulling a 3000 pound trailer.

14 on the highway.

My F-350 with BIGGER diesel engine, more weight, and more wheels gets 17.6 on the highway... actually probably more. Can't remember if I factored in the odometer error--indicated 0.91 miles per actual mile traveled (91 miles indicated per 100 actual miles).

R0oster06 · 03-14-2005, 09:18 PM

wich has more torque ive been itchin to hook up to my buddy who has a 460 under the hood and pull hima round teh parking lot put i dont want to be embassesed and me get pulled around!

-JEremy Roooster!

85Hauler · 03-14-2005, 09:38 PM

[ QUOTE ]
wich has more torque

[/ QUOTE ]

My '86 460 definitely has enough power to do any thing I want but my turboed 7.3 would rip that 460 truck apart. Now hooking my 7.3 to my 500 cadillac powered Chevy dually would be fun. [img]/ubbthreads/images/graemlins/biggrin.gif[/img] I don't think I have a chain that wouldn't break.

d9d · 03-15-2005, 12:54 AM

that -would- be fun to watch!

I wouldn't be surprised if the -peak- torque on the 460 was the same as the IDI. But the HUGE difference with a diesel is that you can get almost full torque all across the rpm range; including all the way down close to idle. The torque-curve for most diesels is almost flat.

Gasser torque-curves, on the other hand, have a pronounced 'hump' shape. They have terrible torque at low rpm's. At 1,000 rpm, I doubt the 460 has more than 200 ft-lbs output; whereas the 7.3 is probably 300+.

That high torque even at idle is what makes a diesel stick so easy to drive. You almost have to -work- at it to stall a diesel stick...not that I haven't done it once or twice...

Mwheeler · 03-15-2005, 01:05 AM

The EFI 460 made peak torque 410lb. ft. @ 2200rpm. I'd say it has pretty good low end.

Mwheeler · 03-15-2005, 01:11 AM

[ QUOTE ]
wich has more torque ive been itchin to hook up to my buddy who has a 460 under the hood and pull hima round teh parking lot put i dont want to be embassesed and me get pulled around!

-JEremy Roooster!

[/ QUOTE ]

Actually it depends on who breaks traction first. If you start spinning he will be dragging you around.

Don't let the 460 fool you--it is not the gutless gasser that many think it is. I have seen a 460 take out a stock '96 Cummins with no trouble at all.

The 460 is good for about 200,000 miles if well maintained. I have seen a few make it to 300,000 but at that point they are extremely tired. That is one advantage to diesel.

I can't say that the non-turbo diesels have better value than the gas trucks, its basically a toss up between the IDI and 460, but its obvious that the PSD trucks do hold value better.

Dualie · 03-15-2005, 10:58 PM

I have both on good day the 460ci 7.5L with now 205,000 miles on the ticker gets 12 mpg with dually wheels on it and 3.75 gears. And for some reason my 7.3L IDIT turbo runs circles around it and gets around 16MPG with 202,000 miles on the ticker I have owned both since new.

Unfortunately though I do have to say the 460 has cost me a lot less in repairs, even considering tune ups. And it eats a lot less transmissions than my diesel!