Builds 1996 LX450 5.3L swap let the fun begin!!

[RockJock82]

My rig averaged 14 city and 17 freeway. The motor was also cammed and had some other power mods. The diesel won't really net you much better numbers. They are averaging combined high teens on mpg. But there is always the difference in cost for fuel as well. I'd like to own both .

 

[half k cruiser]

17 sounds really nice, 20 would be like finding the pot of gold at the end of the rainbow !

 

[alia176]

I'd like to know this as well, I was leaning on a diesel swap but if 20-22 is possible on gas then it would seem to be an easier swap.

I don't think anyone is getting 20mpg with their conversion but if we get at least 17 mpg, that'd be a huge win! I'm lucky to get 14mpg on a consistent basis. These Vortecs produce decent fuel economy in the stock GM platform but seems like that goes down the toilet when that drivetrain is swapped into the Toyota platform that's full of lifts and extra weight.

 

[RockJock82]

We drive tanks on Toyos not Prius's... Something we need to remember

 

[Mr Cimarron]

My rig averaged 14 city and 17 freeway. The motor was also cammed and had some other power mods. The diesel won't really net you much better numbers. They are averaging combined high teens on mpg. But there is always the difference in cost for fuel as well. I'd like to own both .

Yeah 17 beats my 18-20 when you factor in present cost difference between diesel and rug.

 

[RhinoFZJ80]

My confirmed fuel consumption based on calculations i made for the last 3 weeks in the 06 Express Va is 22.1 mpg hwy and 16.8 mpg city. That is an empty van that weighs in at 4823 lbs. Now i started by throwing an additional 862 lbs in the back and threw a cargo box carrier ontop. This got me a staggering 18.7 mpg hwy and 13.21 in the city on stock Goodyear 265/70/17s at 32psi. So i bumped up the tire pressure to a full 42 psi and I remeasured this week and I got 19.3 mpg hwy and 14.85 hwy. So it should be pretty good!

 

[blarsen]

here is the listed mileage for an 02 suburban..
http://www.fueleconomy.gov/feg/bymodel/2002_Chevrolet_Suburban.shtml

 

[RockJock82]

You can gain mileage with a good tune on the PCM also

 

[merbesfield]

Jonathan, are you still running this rig? Sent you PM.

 

[RockJock82]

Pm sent

 

[FeHorse]

How difficult was it to wire the 5.3 up? Did you use the stick harness or pain free?

 

[RiverCityDave]

You know I'm following this thread avidly, and ive got a few thoughts on the mileage. For one thing, most folks (and companies) mileage claims are ina perfect world, everything is optimized, etc. I have a 2000 CRV with a 2.0 liter 4 cyl that when everything is perfect, and I mean the day after a tune up, air pressure perfect, etc I get 23 mpg. Put a bike (just a normal bicycle) on my roof rack and my mileage drops as low as 16.

I have a 2015 GTI that averages 33 on the highway, 29 around town, which honestly is phenomenal for a 2.0 liter turbo that makes 240 hp.

These are real numbers calculated through mileage and usage numbers over months.

Now my cruiser, (94 FZJ with a 1FZ, 33's, 3 inch lift, ARB bumper and roof rack) averages 12 in town and 14-15 highway. That's measured the same way over 3 years of regular usage.

If I get to 18 mpg on the highway, that puts my truck back in play for real trips. Right now, I wouldn't drive it to big bend, or Appalachia, etc. I bought it to use, but it's cost prohibitive.

Combine that with horrible performance on the highway, an even worse in the mountains, and my truck just isn't cost effective or capable for what I want it for. My wife has a 2012 Buick Enclave that gets 23-24 on the highway, and weighs in about 500 lbs less than my cruiser, has a v6 that makes about 300 hp and drives with absolute authority. It never feels under powered, and merges exceptionally well. It drove as well at 9000 ft in Colorado as at 700 ft in the ATX.

So I said all that to say, that if a 5.3 or 6.0 liter swap costs me less than 5k, gets me 17-18mpg and provides me with some power to use when we need it, then it's money well spent, and my truck is a keeper. I know here was a lot of apples to oranges in that post, most of the vehicles I mentioned are very modern, very aerodynamic, and have extremely fuel efficient tires etc, but that is true of the donor vehicles in this scenario too. The 6.0 liter out of a Denali pickup gets about 20-22 highway (which is where I'm most looking for improvement) in the stock truck, which is reasonably aerodynamic, and has modern 20 inch wheels and tires. Once you swap those and or lift the truck, that mileage goes down in most cases to 17-18.

 

[Summiteer]

I've been driving an 02 suburban back and forth to work, about 35 miles each way 25% city 75% highway for the last year. It has a 5.3 with almost 230k on it and I consistently average 19-20mpg. Tons of power and always makes me dream of swapping one into my 80 while I'm driving it. So I would think with just a stocker 5.3 swapped into an 80 with no performance mods or anything these mpg numbers should be within reach. Haven't checked but I would think the Suburban has to weigh more than an 80 does.

 

[RiverCityDave]

At least per the internet, your suburban probably outweighs an 80 by about 500-1000 pounds, depending how it's equipped. I could be wrong, but I would think the drive trains are similar in efficiency, so drivetrain losses should be similar.

The main gain is the power. A few extra mpg don't hurt of course, but I want the drive able horsepower. My wife grew to dislike driving my cruiser because it was so hard to say, merge onto the freeway. I love the 4.5 in my truck, I still haven't ruled out a rebuild and a supercharger, but I spend similar money to not gain any mpg. You know?

Newer tires are 80% as efficient off road as some of the older pure off road tires, but 90% more efficient ON road. I think we will continue to see improvements there. Often overlooked in the hunt for efficiency are things like the type and make up of diff and transfer case lubricants, bearing quality etc. I mean I knowmchanges there get you 1/2 to 1% improvements, but these things all add up.

 

[RockJock82]

Suburbans are not awd also. The power and gain in mileage is what really sells the v8 conversion. Not to mention the nice throaty sounds when you mash the pedal

 

[joemartin]

what is the real cost of this swap?

 

[RockJock82]

there are a lot of variables involved in determining "the real cost" for a v8 conversion. one are you doing it yourself? two how much did your motor and trasmission cost? Are you using a new harness or used one? Unless your paying someone to do the swap its hard to set a cost on it..

 

[joemartin]

i have no idea what any of this costs so im not looking for an exact number as much as im looking for a ballpark of cost. i dont have a motor or transmission and i didnt know i could get a used harness. so just a general idea...

 

[ssyork]

I listed the prices of what I've paid in the second post on my thread. Like RockJock82 said there are so many variables in motor, transmission, harness, even the headers. I just picked up a scratched set for $160, usually they are $255. Also depends on what you can sell of yours. Is your engine blown, is it in great running shape?
Thanks for all the great information RockJock82, it's been super helpful getting my swap going.

 

[NCFJ]

Putting a price to the parts involved in a LSX swap is extremely flexible. First off, there are so many available combinations of equipment. If you are doing a budget swap I would say that absolute bare minimum you can get away with is around $6K. A budget swap will eventually cost you more money that the original parts cost. This is because the areas where corners are cut will start requiring repair.

My feeling has always been, if you are going to a job of the scale of major drive train swap it makes little sense not to totally rebuild the systems that support it, namely the fuel and cooling systems. I also see no value at all keeping stock gauges that were sub standard to begin with. This all drives the cost of the swap up in both money and time.

Start adding changes like a split case and manual hubs, you got it, more money and more time. Lokar shifter ( or other) rather than making worn out stock shifter work. Some folks trust the stock radiator or similar, no thank you. With more HP and Torque comes more heat. Skimping on a radiator is not a wise choice. I go top shelf and use Griffin products, the idea is to make the cooling system a non issue from the start. Cooling issues are not uncommon with Vortec swaps. The motors cool just fine in the donor vehicles.

So it really comes down to what route you choose based on what your needs are and what you can afford to do at the time you choose to do it.

Oh yeah, you might want to service your brakes too