SoCal Jet Boats
Discussion => The No Wake Zone => Topic started by: More2LifeThanMPG on September 01, 2014, 05:17:02 PM
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So couple random questions and concerns; first my major concern is being able to make it to the river without having to stop for fuel! When towing I'm lucky to get 7mpg, not towing I get 10 (but I'm literally 95% side streets)... Now I could understand if I was pulling a monster boat or had a freaky big block, but it's a 350 vortex motor. Yes it is a heavy lifted 4x4 truck, but come on. Also I'm not looking. For anything crazy, if be totally happy if I could 9mpg. Additionally adding a factory replacement fuel tank is out of the question, $1200 for 4 more gallons! That's crazy.
So first thought; I current have the normal broken exhaust bolt. So my thought was while I already have the manifold off install some headers and some good high grade bolts. Now I'm not looking for any gains, and I don't really want to worry about having to deal with smogging long tubes. I was just thinking some cheapo set of shorties? Or is this just a waste of money?
Also I'm lifted and rolling some STT Cooper 35's; I'm pretty sure I'm highly under gear'd for my current application with 3.73's. Is regearing going to make that much of a difference?
And finally I have been told time and time again don't mess with the stock air box in these tucks because they are set up to pull from the best possible place already; I've also been told that the stock tube is the biggest area of restriction. They make a replacement tube assembly, but is it really worth it?
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i feel you on the wanting some mpg gain out of your rig.
im not familiar with your truck....but i can chip in a few pennies gearing. if you re-gear, say to a lower gear, and you keep your larger tire size...what youll end up with is something closer to factory mpg. with the larger tires....it makes the drivetrain act like its in a higher gear than it wants to be. even if just slightly....so your engine works a little bit harder. if you go lower yet again...youll gain some torque and some acceleration, but will spin the motor at a slightly higher rpm, and your mpg will suffer again. in short, a lower gear (depending how low) will bring your truck back to a bone stock feel, or close to it. hope that made sense... :beer:
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10 MPG. :banghead:
Couple stupid ones.
Did you calibrate the speedo/odometer with the new tires?
Second, you lift a truck and put on 35's and now you are bitching about the MPG? :screwy: :screwy:
My '94 Z71 4X4 extended cab towing a 21' day cruiser with a Lance 845 cab-over camper never got less than 13mpg. And that was taking it up through Oregon and Lake Shasta and everywhere in between. when I sold it it had 288,000 or so miles on it and I still see it at least three times a week on the road (the dude owns a Backflow prevention business).
There is something completely wrong with that truck IMHO.
GT
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I had a tahoe that was lifted! hell it got really good gas milage when i towed! it always did better on the freeway than in town. But i did not have my foot to the floor and i do not drive , on the gas or on the brake! big trucks with big tires do coast! id do 60 when towing . That is about it.
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Not bitching about the mpg that I get, I'm more or less asking what can I do to make it to the river without having to stop for fuel... Whatever that answer is, that's what I'm looking for...
I like lifted trucks and understand the dollars it takes to run them, that is not my issue. My issue is efficiency, like you even said something has to be wrong with the truck for it to suck that much! Haha
I've also thought about taking out the spare (that will never work) and figure out how the plumb in an auxiliary tank...?
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I had a tahoe that was lifted! hell it got really good gas milage when i towed! it always did better on the freeway than in town. But i did not have my foot to the floor and i do not drive , on the gas or on the brake! big trucks with big tires do coast! id do 60 when towing . That is about it.
Ha, I actually raring use the brakes while driving. And I'm not too much of a heavy foot. It's a tow rig and DD, not a hot rod. It's the only truck I've had that got worse mpg on the highway towing though.
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10 MPG. :banghead:
Did you calibrate the speedo/odometer with the new tires?
GT
No I have not re-calibrated anything on this truck.
I had a thought of eventually get a custom tune done, but I'm not sure how worth it that is either.
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Oh and i did put a air kit on mine! tire pressure???
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Not bitching about the mpg that I get, I'm more or less asking what can I do to make it to the river without having to stop for fuel... Whatever that answer is, that's what I'm looking for...
I like lifted trucks and understand the dollars it takes to run them, that is not my issue. My issue is efficiency, like you even said something has to be wrong with the truck for it to suck that much! Haha
I've also thought about taking out the spare (that will never work) and figure out how the plumb in an auxiliary tank...?
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With 35's, you should have at minimum 4.10:1 gears. Have you looked into an underdrive? You could just do the rear drive shaft.
It almost sounds like you have a plugged CAT or faulty injectors....
Have you driven it with a scope on it? I would look at the o2 signal switching and the MAP input signal.
Something is screwy..
GT
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Oh and i did put a air kit on mine! tire pressure???
Air kit...?
I run 40 psi, fills the tire nicely but not too much pressure? (At least that's what my tire guy recommended when I purchased the tires like 5000 miles ago)
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No I have not re-calibrated anything on this truck.
I had a thought of eventually get a custom tune done, but I'm not sure how worth it that is either.
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If the speedo is wrong, your actually getting closer to 13 MPG.... It came with 32 " tires... I did Crayon math, but at 60 MPH on the speedo, you are actually going 65...
GT
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With 35's, you should have at minimum 4.10:1 gears. Have you looked into an underdrive? You could just do the rear drive shaft.
It almost sounds like you have a plugged CAT or faulty injectors....
Have you driven it with a scope on it? I would look at the o2 signal switching and the MAP input signal.
Something is screwy..
GT
I have not done any really diagnostic engine anything yet, truly I didn't think it was that big of a problem. I always just thought (big truck + big tires = crappy mpg's)
Apparently I need to look more seriously into the engine. I'm not really a mechanical person, so my information and knowledge is a little limited...
Know I have a couple stupid ones.
What is an underdrive?
Other than a mis how could one tell if an injector is faulty?
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Sorry air raid kit.
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I have not done any really diagnostic engine anything yet, truly I didn't think it was that big of a problem. I always just thought (big truck + big tires = crappy mpg's)
Apparently I need to look more seriously into the engine. I'm not really a mechanical person, so my information and knowledge is a little limited...
Know I have a couple stupid ones.
What is an underdrive?
Other than a mis how could one tell if an injector is faulty?
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I had a Gear Vendor over/under in our motor home... Basically increases the final drive ratio just like a gear change (costs about the same...).
GT
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01 with a 350?? You sure it's not a 5.3?
My 00 Sierra 4wd with a 5.3 on 32s gets 12ish when towing. The stock manifolds on these ls motors flow really well, so I would say don't waste ur time or money on headers, u won't see a difference.
As far as the intake goes, you are 100% correct. I would run the stock box and an air-raid intake tube, I've seen tests that show that's the best setup.
Also I'm sure those 35s with stock gears are definitely not helping matters. Gearing will for sure help, but remember you will have to gear both front and rear the same.
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If the speedo is wrong, your actually getting closer to 13 MPG.... It came with 32 " tires... I did Crayon math, but at 60 MPH on the speedo, you are actually going 65...
GT
I didn't do the math based off the speedo. I did it based off google. I barely made it to the fueling station right off the 62 outside Parker, filled up 25.456 gallons in my 26 gallon tank and that is 243.2 miles from my house. I topped off the morning we left. That put it at 9.5 mpg (so not quite 7 mpg, hahaha)
Another time on the way to Fresno, I had to stop just out of Frowler which is 240 miles and I filled out just under 25 gallons. Which is still 9.5 mpg.
So maybe I'm no that bad...
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01 with a 350?? You sure it's not a 5.3?
My 00 Sierra 4wd with a 5.3 on 32s gets 12ish when towing. The stock manifolds on these ls motors flow really well, so I would say don't waste ur time or money on headers, u won't see a difference.
As far as the intake goes, you are 100% correct. I would run the stock box and an air-raid intake tube, I've seen tests that show that's the best setup.
Also I'm sure those 35s with stock gears are definitely not helping matters. Gearing will for sure help, but remember you will have to gear both front and rear the same.
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It is a 5.3...? I thought that was a 350?
That is basically what I've heard also, one of my cousins is an engineer and works for Spectra and he even said don't waste the money on their intake.
Gears, yeah I have a mechanic at my work that does gears on the side. He said he would do my truck front and rear with a posi lock for $1000.
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I had an 2001 F350 V-10 on 35s I got 9mpg towing ... You need to get some things checked but the biggest problem is if you have never re geared your axles your mileage will never be good
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youd have to take it in...or to some one with a tool that can talk to the computer. not of the code reader variety.
an under drive is like another set of gears...which are usually lower... in a case that attaches to the end of your trans. this again would help get you closer to the optimal road speed to engine speed ratio.
an engine tune may free up a few ponies....maybe even increase your mpg. but not if engine has issues....check engine light on? bad o2 sensor will kill mileage. re-calibrating speedo....doesnt increase anything. just adjusts or calibrates your speedo to work with your bigger tires. larger tires spin slower so they read slower. keeps everything closer to factory specs, shift points, etc. youll need a device to plug in to calibrate, i think....
i would start with simple stuff....cheap or free stuff first. like tire pressures. if the tire says it needs X pressure....you should be at that pressure. too low and mileage goes down. tires on trailer? brakes dragging on trailer? clean air filter on truck? i never noticed an impressive increase with an aftermarket intake....but, maybe your truck would respond better to one than mine. at least a better/clean filter. clean fuel filter? after that....may need to hook up a device to see what your engine is doing. if all is well....may need to put lower gear in. these are things id check...not definitively speaking.
also, to find mileage using your speedo (if corrected), when you fill up.... reset your trip meter to zero...when you go to fill up again or put any amount of fuel in, note the amount of gallons ...divide number of miles on trip meter by the number of gallons you put in...this will give you your actual usage.
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No check engine lights on, and my trip meter doesn't work. I keep a long of mileage and the amount of fuel I filled up, I know it's off but it's pretty close as probably 90-95% of my none tow driving is on side streets.
And that's pretty much why I started to not worry about a tune, was going to regear because I think that would help more than anything. But I do notice the truck doesn't make power where it's suppose to and the shift points are a little weird, I figured the gears would fix that too.
Then the exhaust leaks issue came up, sadly in the same weekend that the boat also got an exhaust leak...
I changed the air filter when I purchased the truck a little over a year ago, and I blow it out every oil change. It doesn't look clogged, but I can swap it out.
If I wanted to take it in and have it looked at, what should I say? (Because telling my buddy I get crappy mpg's isn't going to work, he's going to laugh and say I told you not to get a lifted truck) haha
Trailer- doesn't have brakes connected (that was one of those I'm going to do when I redo the trailer, that was last winters project...) and tires are aired up to 55 psi, and they have good thread. A couple years old but still good. I don't think it's a trailer issue.
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Just talked to my dad. He has a 2000 Silverado 4X4 with a 5.3L and has nearly 300,000 miles on it, he has a JET MAF, Borla muffler, smog legal as the day it was bought and he regularly gets 22 MPG. He said when he tows the big boat (23' triple axle trailer about 5,000lbs) he gets 14-16 depending on how white he wants to drive..
You my friend have broken chit.
GT
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so....you have an exhaust leak. i wouldnt be surprised....if your suckin in air thru that leak....cause the o2 sensor to read a leaner fuel mix than actually present and compensating for it. meaning the comp will squirt more gas in than it needs based on o2 reading. this will not give you a code as the engine doesnt see anything wrong. exhaust leaks suck. just like a bad 02 sensor.
if you have a line on someone who can hook it a scan tool....you can tell them to check to see if engine is running according to spec. maybe ask them about that exhaust leak....see if its causing engine to run a tad richer than usual.
maybe see if he can calibrate your speedo.
you can use your odometer to calculate mileage just the same....just a little more math figuring out start/stop miles.
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Just talked to my dad. He has a 2000 Silverado 4X4 with a 5.3L and has nearly 300,000 miles on it, he has a JET MAF, Borla muffler, smog legal as the day it was bought and he regularly gets 22 MPG. He said when he tows the big boat (23' triple axle trailer about 5,000lbs) he gets 14-16 depending on how white he wants to drive..
You my friend have broken chit.
GT
Sweet... So that is possibly something wrong. Well that's better than having to just deal with, I can work in chasing down a problem! Makes me feel good and bad all rolled into one.
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Start with the exhaust leak!if its at the manifold you can ruin exhaust valves!!!! just so you know a 5.3 is about a 327 Not a 350
A 350 is 5.7
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leave your stock air intake alone if you're worried about your mpg. more air = needs more gas.
if you REALLY want to know what your car is doing get one of these:
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi694.photobucket.com%2Falbums%2Fvv308%2Fdixie_boysles%2F2010-12-25102200-1-1.jpg&hash=d6c314c971e09427996f480e1654b9bfc4dea21a)
its called an "ultra gauge" and it costs about $60. it plugs into your vehicles ODBII port and it will give you EVERY detail about your car. maf, throttle position, o2 sensor readings, fuel trims, cam advance, timing, spark, etc. you'll know exactly why you're burning excess fuel.
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Have your credit car standing by. :sly:
https://www.gearvendors.com/4x4gm4s.html (https://www.gearvendors.com/4x4gm4s.html)
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leave your stock air intake alone if you're worried about your mpg. more air = needs more gas.
Not if it's anemic. :-\
GT
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I have a 2001 Tahoe 4x4 with 410 gears and I tow from Palmdale to Laughlin on a tank of gas no problem and I've got a 130 thousand miles on my ride.
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Stopping for fuel sucks, especially when you have to maneuver a trailer around the station. I had a v10 on 37s that burned about 30 gallons one way with out towing. Luckily it had the long bed tank, because that truck had the turning radius of a school bus so tight maneuvers with a boat suck.
Do some research on the Suburban tank. I'm sure there has to be a way to mount one under a tahoe. I think the burb comes with a 34 gallon tank.
I pulled my boat home recently with my 08 tahoe. It gets there (270 miles) with a half a tank unloaded, but it will burn the entire tank with the boat behind it.
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Start with the exhaust leak!if its at the manifold you can ruin exhaust valves!!!! just so you know a 5.3 is about a 327 Not a 350
A 350 is 5.7
That's the plan, that's why I was asking about headers. Figured it'd be a good time since your already in there and have it all taken apart. But it sounds like headers are going to be a waste of money, if the manifolds are still good.
And thanks for the displacement adjustment.
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Have your credit car standing by. :sly:
https://www.gearvendors.com/4x4gm4s.html (https://www.gearvendors.com/4x4gm4s.html)
Holy cow poos!!
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leave your stock air intake alone if you're worried about your mpg. more air = needs more gas.
if you REALLY want to know what your car is doing get one of these:
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi694.photobucket.com%2Falbums%2Fvv308%2Fdixie_boysles%2F2010-12-25102200-1-1.jpg&hash=d6c314c971e09427996f480e1654b9bfc4dea21a)
its called an "ultra gauge" and it costs about $60. it plugs into your vehicles ODBII port and it will give you EVERY detail about your car. maf, throttle position, o2 sensor readings, fuel trims, cam advance, timing, spark, etc. you'll know exactly why you're burning excess fuel.
Does this thing log any data? Or is it just real time readings? There website didn't really say either way.
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Does this thing log any data? Or is it just real time readings? There website didn't really say either way.
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Live view only no logging. Can pull codes as well. Its about the size of a business card but thicker obviously.
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More . . . MPG, just how exactly did you decide on your screen name here? Having second thoughts?
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Just for knowledge all suburban tanks are 44 gallons i would gi to the river and back fully loaded with people gas cans ice chest for 3-4 days of dry camping plus my old 18 ft tri hull all gear very heavy grabbing 2nd gear to climb baker grade and only used about 3/4 of a tank round trip. 99 burb 5.7 2wd with a chip and flow master. My 00 Silverado 5.3 is 3/4 a tank to parker and a tank back says 14 mpg
big river chris
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Go back to stock? Lol. If you want a lifted brodozer with fair mileage go buy a diesel, I have an 04 Tahoe bone stock with a 5.3 also with 3.73's and towing I get 16.2 avg going to and from our river house.
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If you want to calculate for a new gear ratio, use a proportion to get you back close to stock RPM at highway speeds. Round to a lower gear ratio (numerically higher) for increased torque multiplication to help with the increased rolling/aerodynamic resistance of your lifted truck.
New Ratio New Tire Diameter
--------------- = ----------------------------
Old Ratio Old Tire Diameter
Here is how the numbers worked out for my Jeep
New Ratio 35
--------------- = ------
3.73 30
New Ratio = (3.73 * 35) / 30
New Ratio = 130.55 / 30
New Ratio = 4.35:1
4.33:1 would be within 1%, if it was available, except the closest ratios available for my axle are 4.10:1 and 4.56:1. 4.56:1 puts me at 4.6% of my target which will increase my RPM from 2100 @ 65MPH to 2196RPM. However, 4.10:1 would yield ~68MPH @ 2100RPM. Again, the added torque multiplication will help overcome the added resistance caused by the lift and bigger tires.
Too low of an RPM will lug the engine and consume more fuel just like winging it up.
If you want to be more accurate, substitute tire roll-out for tire diameter. Just make sure that gear ratios are on one side of the equation and tires are on the other and that new are both on either the top or the bottom with the old being on the other.
Good luck,
Joe
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I pulled my boat home recently with my 08 tahoe. It gets there (270 miles) with a half a tank unloaded, but it will burn the entire tank with the boat behind it.
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Mine tows to the river on just past half a tank.
-beerjet-
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Just for knowledge all suburban tanks are 44 gallons i would gi to the river and back fully loaded with people gas cans ice chest for 3-4 days of dry camping plus my old 18 ft tri hull all gear very heavy grabbing 2nd gear to climb baker grade and only used about 3/4 of a tank round trip. 99 burb 5.7 2wd with a chip and flow master. My 00 Silverado 5.3 is 3/4 a tank to parker and a tank back says 14 mpg
big river chris
Used to have a 97 sub, loved and hated that tank! It wouldn't even flitch at $100 but it would go forever. Haha
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Go back to stock? Lol. If you want a lifted brodozer with fair mileage go buy a diesel, I have an 04 Tahoe bone stock with a 5.3 also with 3.73's and towing I get 16.2 avg going to and from our river house.
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I have thought about a diesel, but they were all out of my down grading price range. And now I need to keep this current truck a little while to make it worth it for me.
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More . . . MPG, just how exactly did you decide on your screen name here? Having second thoughts?
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No I like driving and having a good time... I want to do more of it! Without having to stop as much.
Like I said if my only option is to have a bigger tank, I would like ideas on how to do that with a reasonable budget... Haha
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If you want to calculate for a new gear ratio, use a proportion to get you back close to stock RPM at highway speeds. Round to a lower gear ratio (numerically higher) for increased torque multiplication to help with the increased rolling/aerodynamic resistance of your lifted truck.
New Ratio New Tire Diameter
--------------- = ----------------------------
Old Ratio Old Tire Diameter
Here is how the numbers worked out for my Jeep
New Ratio 35
--------------- = ------
3.73 30
New Ratio = (3.73 * 35) / 30
New Ratio = 130.55 / 30
New Ratio = 4.35:1
4.33:1 would be within 1%, if it was available, except the closest ratios available for my axle are 4.10:1 and 4.56:1. 4.56:1 puts me at 4.6% of my target which will increase my RPM from 2100 @ 65MPH to 2196RPM. However, 4.10:1 would yield ~68MPH @ 2100RPM. Again, the added torque multiplication will help overcome the added resistance caused by the lift and bigger tires.
Too low of an RPM will lug the engine and consume more fuel just like winging it up.
If you want to be more accurate, substitute tire roll-out for tire diameter. Just make sure that gear ratios are on one side of the equation and tires are on the other and that new are both on either the top or the bottom with the old being on the other.
Good luck,
Joe
Thank you for the breakdown and making since of the math, I found a graph online that seemed to make since.
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Mine tows to the river on just past half a tank.
-beerjet-
Big River or Needles?
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Big River or Needles?
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Big river.
The drive back from Needless eats up the entire tank sometimes.
Between the hills and diving into the wind... fock that drive.
-beerjet-
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Just wait till the October trip lol
big river chris
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Big river.
The drive back from Needless eats up the entire tank sometimes.
Between the hills and diving into the wind... fock that drive.
-beerjet-
Haha, yeah, Big River is an easier driver. Between the wind in Victorville and the grades (especially coming back), my truck will burn fuel.
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See now on the way back from blue water I didn't burn as much gas, but we also left at 7pm with he boat nearly empty. Going there it was slightly under half and we left here at 8am-ish.
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