What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

lift vs mpg ...

R

rcurrier44

1/2 ton status
Joined
Oct 13, 2003
Posts
320
Reaction score
0
Yes I have been searching.

Its obvious that the higher you lift a rig the more aero-drag you are going to get. But how much of an effect is it realy. With rising gas prices this has become a consern of mine.

I am thinking about doing a 3"-4" lift on my DD. There are some trails that I don't need (or want) to bring my big wheeling rig on. Currently my DD is a 76 1/2 ton chevy with a 350/th350/203, 3.73gears, 34x10.5's and a stock suspension. I would like to get some more uptravil (currently only 1.75") in the front and more flex out of the suspension. I get about 10mpg city and 13mpg highway; witch I consider respectable.

So, has anyone lifted their truck without changing gearing/tiresize/engine and kept track of their MPG?

Thanks
ROB
 
If you are not going to increase the tire size you would probably only need to put on a 2 or 2.5" lift to get decent flex (depending on what springs/shocks you choose). I dont think the lift alone will change your gas mileage too much compared to changing to wider tires.
 
The reason I said 3-4" is because I would be using a set of modified 52" rear springs. They are terably saged after being in a 79 suburban all their life, but not bent. I am planning on pulling the overload and adding 1 short and 1 long leaf to the pack.

I do have an add-a-leaf/stock front 2.5" pack around but don't like how stiff the ride is.

One of the goals of this rig is to keep it as cheep as posible...I currently have just under 300$ cash-outlay in the hole truck /forums/images/graemlins/grin.gif I realy enjoy rubbing that in my Ford buddys faces, and want to keep this as low buck as posible. /forums/images/graemlins/thumb.gif
 
Well, since you already have the springs, just throw them in and recheck your mpg. If you can live with it keep it, if not return it to stock. Not like the mod will cost anything but a little time at this point /forums/images/graemlins/thumb.gif
 
Good point, I have a set of 2.5" blocks I could throw in the back for now (shackle flip later) to level it. I could also get away with the push/pull steering for now also.

I was just hoping someone might have some first hand experience.
 
With trucks like ours, you just have to bite the bullet about the gas mileage man.
Just can't think about anymore. /forums/images/graemlins/deal.gif
 
[ QUOTE ]
With trucks like ours, you just have to bite the bullet about the gas mileage man.
Just can't think about anymore. /forums/images/graemlins/deal.gif

[/ QUOTE ]


I hear that...
 
I didn't see much difference when I lifted my 78 4" and put 35s on, but when I went from 3.73 to 4.09 and from 4 to 6" I saw a pretty big difference.
 
[ QUOTE ]
Yes I have been searching.

Its obvious that the higher you lift a rig the more aero-drag you are going to get. But how much of an effect is it realy. With rising gas prices this has become a consern of mine.

I am thinking about doing a 3"-4" lift on my DD. There are some trails that I don't need (or want) to bring my big wheeling rig on. Currently my DD is a 76 1/2 ton chevy with a 350/th350/203, 3.73gears, 34x10.5's and a stock suspension. I would like to get some more uptravil (currently only 1.75") in the front and more flex out of the suspension. I get about 10mpg city and 13mpg highway; witch I consider respectable.

So, has anyone lifted their truck without changing gearing/tiresize/engine and kept track of their MPG?

Thanks
ROB

[/ QUOTE ]Do you plan on keeping the same 34" tires? Gear ratios effect MPG more than the lift IMHO. First off 10 & 13 is EXCELLENT for a carbed rig with a th350. I doubt you would lose much with the same rubber and only 3-4" taller. If you do go bigger tires than that is where you will see a big difference. /forums/images/graemlins/waytogo.gif
 
The gearing and choice of wheels/tires will have more effect than a few inches of lift.
 
[ QUOTE ]
Do you plan on keeping the same 34" tires? Gear ratios effect MPG more than the lift IMHO. First off 10 & 13 is EXCELLENT for a carbed rig with a th350. I doubt you would lose much with the same rubber and only 3-4" taller. If you do go bigger tires than that is where you will see a big difference. /forums/images/graemlins/waytogo.gif

[/ QUOTE ]

Yep I am keeping the same tires. I may eventualy go to a 33x12.5 but I will also be changing to a manual transmission by that time.

I thought 10-13 was about normal. My old 79 blazer was getting 16mpg highway at sealevel with a 350/th350/203, 36x14 tires, a 7" lift and 3.75 gears. But I also ran the tires at 45psi and the engine was much stronger than this one.
 
dumb question: why lift the DD at all?

j
 
Id say 10-13 is good now. When my truck was stock it got about 8 mpg around town, gotta be the cam. With the lift and all (14"), I get 12 on the freeway, hopefully even better with the TPI! /forums/images/graemlins/peace.gif
 
I saw a big difference with my lift mainly on highway driving, i have driven a few times from Phoenix to SoCal area before the lift and after the lift and about the same size tires, just in 16" measurements, i have used quite abit more fuel, also the wind drag and "movement" of the truck is quite abit more noticable at highway speeds.

I don't think people really pay much attention to these little details after they lift their trucks, because they know something is going to change and just get used to the change, but fuel mileage DEFINATELY changes for the worse when they are lifted, like you say, more areodrag, more wind under the vehicle is bad for the mileage.
 
It really depends if you have overdrive or not. Non overdriven rigs generally have enough power that they never feel the difference.

Overdriven rigs it makes a tremendous difference even going from 2-4" made a huge difference on mine when it had overdrive.

Going from 4" with overdrive to 9" without overdrive netted minimal difference compared to previously going from 2" to 4" while having overdrive.
 
[ QUOTE ]
dumb question: why lift the DD at all?

j

[/ QUOTE ]

Cuz I can't leave good enough alone. /forums/images/graemlins/whistling.gif I am realy just looking for a little more uptravil in the front. Some more flex would be nice too. I would like to keep this one as a work/hunting/mild wheeler only and get a AWD car as a DD; but I already have 5 vehicles myself (not including the line of parts rigs) girlfriend has 2 more. I am realy fighting the urge to get another.
 
[ QUOTE ]
[ QUOTE ]
Do you plan on keeping the same 34" tires? Gear ratios effect MPG more than the lift IMHO. First off 10 & 13 is EXCELLENT for a carbed rig with a th350. I doubt you would lose much with the same rubber and only 3-4" taller. If you do go bigger tires than that is where you will see a big difference. /forums/images/graemlins/waytogo.gif

[/ QUOTE ]

Yep I am keeping the same tires. I may eventualy go to a 33x12.5 but I will also be changing to a manual transmission by that time.

I thought 10-13 was about normal. My old 79 blazer was getting 16mpg highway at sealevel with a 350/th350/203, 36x14 tires, a 7" lift and 3.75 gears. But I also ran the tires at 45psi and the engine was much stronger than this one.

[/ QUOTE ] I mean this in no offense but are you shure you are getting the MPG numbers right? It is fairly easy to get off by a few miles or have an extra gallon in there or something. Remember that the odometer is not correct anymore(along with the speedo) when you go with bigger tires. Reason why I ask is because 16 is EXTREMELY good for a carbed truck with that much lift, gears, and tires. Most TPI rigs have a hard time getting that with optimal gearing/tire conditions. I get around 10-12 on the highway with a th700R4 behind my built 406 , although I am running 10" of lift and bias tires. /forums/images/graemlins/thinking.gif, and about 9mpg in town.

Like I said, gears and tires are going to make the biggest difference, 3-4" of lift would make almost no difference in town and minimal on the highway. With the 33's you want I would run a 4.10 ratio, good MPG vs. performance.
 
You must log in or register to reply here.

Latest Posts

Top Bottom