Just wondering if anyone has a direct or good before/after results with installing a turbo and getting better mpg at light cruising speeds and city driving.

Looking at all the diesel trucks they get great mpg's but they all have turbo's, the earlier diesel trucks that didn't have a turbo got nearly half mpg's

Reason I ask is because I'm trying to get better mpg from my truck.

It is a 1988 dodge ram with a 440 in it, 2500 stall, 727 trans,full time np203 t-case, 3.90 gears, 31 x 12.50 tires, 4600lbs ,lifted 4 inches, carb 750 demon, stock truck cam with .420 lift, edelbroke aluminum heads, headers.

Now its gets 9.1 mpg in the city and on the highway. Considering the mods I didn't think that was horrible considering the mods and tranny not being OD

Some newer trucks get only 12-14 with an od tranny and a part time t-case with a smaller motor.

Engine has a ton of TQ and I'm thinking about a OD swap(looked into it should only cost $800 or so getting craigslist parts and doing labor myself)

A more stock stall of 2000 vs my 2500 may get 1 mpg, also the OD tranny should be good for 3mph on highway. and a newer t-case that is ligher and more efficient may help slightly so that may put me 10 city and 13 highway

LOL still not great but for $800 vs a new truck you cant even pay sales tax for that.

engine is 8.5 compression so I think I have two routes, up compression to 9.5 or 10:1 and getter better mpg from that or do the turbo if its been proven to get better mpgs with the right size turbo, setup, ETC.

Any info , tips, web sites, and opinions are open, besides selling the truck..LOL

http://www.youtube.com/watch?v=DInhf1I-BmM

I like the truck and I just want to improve it and make it better/ more efficient, LOL I know the burnout does not make it get better mpg. 9 mpg's is the best I can do driving it easy.

I was also wanting to maybe lower it just and inch all the way around for better areodynamics.

 

Also with my cam being a flat tappet .420 lift ? duration..stock from 1978 I wonder if a decent roller cam conversion with similar specs to a ls1 will get better mpg and power. With my ls2 camaro and tv.2 cam setup I went from 21mpg on the highway with an ls1 10.5 compression 224 227 .563 .569 lift cam to 22mpg on highway with the ls2 bigger motor 11.0 compression and bigger cam.

I hear alot of people gain mileage from a bigger cam, but not to big. may need to call comp on this one.

 

The cost of the turbo will never offset any gas savings unless you drive your truck a **** ton of miles. Even then the extra maintenance cost will offset all of that. Not to mention at WOT, which you will do sometimes, it will guzzle fuel.

 

OK, thanks for the input, I'm still wanting to do the OD converstion as that should help quite a bit for the price I can do it for.

Do you have any results though or guesses for gains?

 

If this thing holeshots anything like your camaro, it will take my vette from a dig lol.

 

Tall order. Both of my 20 ft box work trucks get better than 9. Last tank in the Penske truck was over 12.

You look like you like to drive it, got some pride in it, why not.

I'd say F it and put a 24 valve junkyard cummins from a late 90's with an hx40. You'd get all the MPG's you're looking for and more power.

 

that cam is puny for at 440. replace the cam with one that has in the neighborhood of 212-220@050 duration and it will wake up the engine nicely. the problem then will be it's too much fun too keep the foot out of it. just like a turbo.

 

+1. I'd sell the 440 if you're looking for MPGs. Put a 5.3 turbo in it. That'll make things lots better. **** off the MOPAR gods.

 

LOL , jeah if i could do it all over again thats what I would do, or the ls1 and a 6 speed with 4.56 gears. But I have to much time already in it and money to scrap it. plus its a fresh 440.

If it matters I swapped the brake booster from a 98 camaro onto it, stoops alot better and its lighter by 6lbs..LOL

Today I just got back from IL from buying a 700r4 and np208 case. There is my overdrive, maybe another 3-4 mpg. the 700r4 and np208 are nearly 200lbs ligher then my 727/np203. so yeah chevy tranny is going in the dodge!!

 

LOL, doesn't leave the line quite like the camaro, but it did cut a 1.99 60' on the pro comp mudd terrains..

 

I think I will get over 122 mpg once i swap the tranny and t-case.

I thought about the cummins swap, but there is are two big downfalls, One they sound like ****, just like vipers, and secondly I hate all the black smoke.

Your work trucks most likely have an od tranny and a turbo, scrap both of those and your down to where I'm at.

 

http://tiresmoke.iwarp.com/700R4%20i...%20Duster.html

Nice, gained 5mpgs from going to a gm tranny, aparently the 727 is a hp robber, I have the 700r4 and np208, as soon as my adaptor plate comes in I will begine the swap and may do a write up on it as well. Looks like I should gain 4-5 mpg's

 

at 80mph in 6th gear i'm getting about 23-25mpg... 385cu.in., 3.42 gear, a needle width or 2 below 2000rpm's

 

Thanks for the advise!!!LOL

 

I still get 20 mpg with 80 lb inj, 370 with th400, steel driveshaft and 12 bolt.

Thats with driving 5 hours away to a track trapping in the 140s and driving home.

 

what gears did you decide on?

 

That was with 26 inch tall tire and the 3.42s, I have 3.08s going in now, waiting on parts to show up that ended up bad in my rearend. Next change gear wise will be gear vendors over drive.

 

im guessing their was a fair amount of highway driving in this? I dont have a calculator handy, what kind of RPM were your turning at highway speeds?

 

Daily driver, yes it's driven all over. Was doing 55 mph at 2500 - 2600.

 

How can you only go 55mph, lol. Ive weighed this issues deciding on what to do about my next trans. I dont think i could do only 55mph, lol