cummins or 6.0 lq4 which one is better?

[lkefthrlkeson]

Been noticing a lot of lq4 and cummins swaps on here. Just wondering which one has the most advantages as far as gas mileage, power, etc.. Do they cost about the same to do? Can you use a 4l80e with a cummins? Gonna get used a lot for my spray business, so I want it to be able to hold up either way. Thanks for the replies....

[b454rat]

LQ4 needs a computer to run, early Cummins don't. That right there is a major selling point for me. LQ4 is crazy expensive to buy, I'm getting 3 $1800 or so.

If you have the adapter you can bolt up a 4l80, but will need a stand alone computer to shift it, or go manual valve body.

I'm a diehard Gm guy, but can't beat a Cummins.....

[lkefthrlkeson]

[QUOTE=b454rat;4308660]LQ4 needs a computer to run, early Cummins don't. That right there is a major selling point for me. LQ4 is crazy expensive to buy, I'm getting 3 $1800 or so.

If you have the adapter you can bolt up a 4l80, but will need a stand alone computer to shift it, or go manual valve body.

I'm a diehard Gm guy, but can't beat a Cummins.....[QUOTE]


I saw that you were planning on doing a cummins swap here pretty soon. Just a couple of questions... How much does a good used cummins cost? Where is a good place to get a deal on one? What all is involved in swaping from gas to diesel etc...?

[camshaftgsxr]

if its a two wheel drive lq4/9 all the way, if its a 4x4 do the cummins

the ls series engines arent that hard to swap in as long as you use a stand alone harness or a camaro harness, the truck and suv harnesses have an anti theft feature i havent figured out yet..

[Clyde65]

They all have the anti theft feature in the PCM/ECM ( not the harness)after I think 2000/2, it just needs to be programed out, pretty easy for a tuner or someone with the software available.

[camshaftgsxr]

thanks clyde, my girlfreinds dad has a 6.0 swapped 64 panel wagon, asked him after i posted and he told me,

[jitteryguy]

Originally Posted by camshaftgsxr

if its a two wheel drive lq4/9 all the way, if its a 4x4 do the cummins

why do you say 2 wheel drive LQ4 ? I'm want'n to put the 12V Cummin's in my 2 wheel drive dually, is there width issues ? the only ones I've seen were in 4X4's , I noticed they notch'd the frame for the AC. is this the issue ?

[camshaftgsxr]

Originally Posted by jitteryguy

why do you say 2 wheel drive LQ4 ? I'm want'n to put the 12V Cummin's in my 2 wheel drive dually, is there width issues ? the only ones I've seen were in 4X4's , I noticed they notch'd the frame for the AC. is this the issue ?

well i would put a cummins in your dually too i meant in a 2 wheel drive short bed single cab (the smaller trucks)

<< like that one

[lkefthrlkeson]

thanks for all the replies guys... I think I'm gonna go with the lq4/4l80. Good power, decent mileage, and they're good for at least 200k miles. Hopefully, I can find a low mileage one for a good price.

[Clyde65]

I have had pretty good luck with LKQ here in North Texas, you might want to give them a call.

[496 BB]

Search here for the engine. http://car-part.com/


a LQ4/9 WILL NOT even come close to TQ outputs of a Cummins. Mileage will also be better in Cummins. Cost is where the Cummins comes into play. That and if you want an automatic you will need to have one built that was made to go behind a cummins unless you want to spend lots of money fabbing up something else. You can always get a NV4500 5 speed to go behind them also but need a better clutch than stock if you plan on putting some power out...which you will once you drive it. I have a good friend who is finishing up putting an Allison behind a Cummins in a 99 Silverado. Its been a PITA to say the least. Cummins is alot more expensive than going gasser.

LQ4/9 on other hand is what Im planning on doing next year. These motors are excellent motors for building power reliably. Stock bottom ends will hold more than you will likely throw at it. Throw a nice spec'ed cam and set of heads and your sitting pretty. Just a cam will net around 60 hp if tuned right. You DO NOT need to go fuel injection with this setup either. You can carb it also as both Edelbrock and MSD have kits to convert and still retain stock coil packs with preset ignition curves. Look here.... http://www.jegs.com/p/Edelbrock/Edel...55239/10002/-1 The best thing is with the LQ4/9 you can keep the TH400 trans if you want with minor changes. You can also use stock harness if going FI and build your own. OR you can goto multiple places and have them custom make you one but are usually around $400-$600+ to get.

Another option you have is getting what I got in my HD which is an 8.1L (496ci) motor and mate it to an Allison or a TH400. Trust me with the tuning I got on here its nuts. You have not driven one of these until you get an EFI Live tune and no TM anywhere. I am in between the two motors and leaning towards the LQ4 for gas mileage since I plow in winter and mud in summers with it.

[draggin86]

umm LQ9 by far its a modern motor getting you better MPG and HP..

[Dieselwrencher]

I wouldn't even mess with a gas engine for a tow vehicle, or a hauler if I was considering doing a cummins swap. Reliable, fuel efficient, and cheap power, 12v that is. What more do you need?

[Dieselwrencher]

Originally Posted by draggin86

umm LQ9 by far its a modern motor getting you better MPG and HP..

In a dually? I think not. I'd put my dinosaur 12v up against a LQ9 in a heavy truck any day. Then go hook up the trailer and go run some hills.

[clinebarger]

Originally Posted by lkefthrlkeson

Been noticing a lot of lq4 and cummins swaps on here. Just wondering which one has the most advantages as far as gas mileage, power, etc.. Do they cost about the same to do? Can you use a 4l80e with a cummins? Gonna get used a lot for my spray business, so I want it to be able to hold up either way. Thanks for the replies....

A 6BT Cummins with a P7100 injection pump will have better milage, more power potential, & last alot longer.

As far as using a 4L80E behind a Cummins...I whould not recommend it, as strong as they are it whould not last, They may handle 1000hp but it cant handle 750 ft lbs at 1400 RPM. A 47RE or a 48RE Dodge can be built stronger.

[b454rat]

I thought the lq4 was the Duramax??

For any type of towing I wouldn't use a gasser. I never owned a diesel, towed a lot with gasser's , but like already said, can't beat a Cummins for power, upgrading, economy, durability, etc.

I'm getting a Cummins that is rated at 175 horse. Doesn't sound like a lot, but torque is 450-ish. Get a #100 fuel plate, those numbers go to 250-ish horse and 620 ft/lb of torque. For about $200.

http://www.puredieselpower.com/catal...ate-p-451.html

[D.FENS]

You're saying the truck will get used for your business, right? The diesel would be better for towing and / or hauling, but you gotta think it through in terms of how long it'll take to get enough use out of the truck to recoup the investment.

The buy-in on the diesel swap is a little cheaper, but most people who do Cummins swaps don't leave them stock ($$$) and the transmission / drivetrain mods to support 1000 - 1500 ft/lbs of torque ain't free either.

I'm eying up an LSx swap for my dually, because the only towing I do is a tow dolly or 20' single-car trailer, and seldom haul anything heavy (still think sometimes I bought too much truck for my needs but too late now).

[N2TRUX]

Another thing to factor in is fuel costs. Around here diesel fuel is still much higher than gas. Besides, who wants to fuel up at those stinking diesel pumps.

[lkefthrlkeson]

Originally Posted by D.FENS

You're saying the truck will get used for your business, right? The diesel would be better for towing and / or hauling, but you gotta think it through in terms of how long it'll take to get enough use out of the truck to recoup the investment.

The buy-in on the diesel swap is a little cheaper, but most people who do Cummins swaps don't leave them stock ($$$) and the transmission / drivetrain mods to support 1000 - 1500 ft/lbs of torque ain't free either.

I'm eying up an LSx swap for my dually, because the only towing I do is a tow dolly or 20' single-car trailer, and seldom haul anything heavy (still think sometimes I bought too much truck for my needs but too late now).

Yes it will get used alot during spray season. I have a 300 gallon spray rig that will get mounted in the bed of the truck(much easier to maneuver down lease roads than hauling a trailer). That's really the biggest it will carrying. Hope that gives a better idea of what it'll be used for.

[496 BB]

Originally Posted by b454rat

I thought the lq4 was the Duramax??

For any type of towing I wouldn't use a gasser. I never owned a diesel, towed a lot with gasser's , but like already said, can't beat a Cummins for power, upgrading, economy, durability, etc.

I'm getting a Cummins that is rated at 175 horse. Doesn't sound like a lot, but torque is 450-ish. Get a #100 fuel plate, those numbers go to 250-ish horse and 620 ft/lb of torque. For about $200.

http://www.puredieselpower.com/catal...ate-p-451.html

Duramax is either codes LB7 (01-04.5), LLY (04.5-06), LBZ (06-07.5), LMM (07.5-2010), and new one is LML. LB7 was non emissions BS motor and non variable vain turbo.

If your getting a 6BT Cummins complete and running for $200 thats a HELLUVA a deal.

Originally Posted by N2TRUX

Another thing to factor in is fuel costs. Around here diesel fuel is still much higher than gas. Besides, who wants to fuel up at those stinking diesel pumps.

Provided the better mileage you get in a diesel you will still be saving money even paying slightly more in fuel.

[496 BB]

Originally Posted by lkefthrlkeson

Yes it will get used alot during spray season. I have a 300 gallon spray rig that will get mounted in the bed of the truck(much easier to maneuver down lease roads than hauling a trailer). That's really the biggest it will carrying. Hope that gives a better idea of what it'll be used for.

So you figure a gallon of water weighs about 8 lbs. Just for ****s and giggles lets say so does your spray. 8x300 gallons=2400lbs. Thats NOTHING. You can go either way and be totally fine in towing that. Even if it was 4000lbs I wouldnt be worried about the motor....springs and lack of air bags yes but not motor.

I would go whichever route is the easiest to afford and put the money you would be saving back into your business. Trust me when I say you will need the capital.

[N2TRUX]

Originally Posted by 496 BB

...Provided the better mileage you get in a diesel you will still be saving money even paying slightly more in fuel.

Not from what I have been told by several diesel truck owners. It will depend on the price in your region, but here in South Texas you will pay a LOT more for fuel.

[joe231]

up here in the middle of Oklahoma diesel is @ 50 cents more a gallon.....
what are some real world MPG numbers for the 6BT? And the LQ4? I know a few guys with newer crew cab 4x4 3/4 ton trucks with the LQ4 stock, they are lucky to Get 14MPG. I also know a guy with a 2001 dodge SRW 1 ton extra cab long bed, with a tune getting 20+MPG.
I'm not familiar with what year Cummins are what, but to compare those 2 numbers, the LQ4 with gas @ $2.50 a gallon is 18 cents per mile cost verses the Cummins fuel at $3.00 a gallon is 15 cents per mile....I'm not sure if this is a apples to apples comparison, and the wear and tear parts replacement for the Cummins are probably going to be more expensive also.

[0331grunt]

I have a stock '06 1 ton Ram MegaCab with Cummins, 6speed manual, and 4x4. I pull 12-15k lbs regularly and still average 13+ mpg. When not towing, I get 19-22 easy. I only have a 4" straight pipe and intake as the only upgrades and I have 325hp/600tq. Will be getting a programmer soon. I would go with a Cummins in a heart beat, regardless of price of fuel. just my $.02..

[lkefthrlkeson]

Originally Posted by clinebarger

A 6BT Cummins with a P7100 injection pump will have better milage, more power potential, & last alot longer.

As far as using a 4L80E behind a Cummins...I whould not recommend it, as strong as they are it whould not last, They may handle 1000hp but it cant handle 750 ft lbs at 1400 RPM. A 47RE or a 48RE Dodge can be built stronger.

First off, thanks for all the replies so far.

So what are people doing about the transmission in a cummins swap? Definitely want an automatic. What are most people paying for a good used cummins engine?