Modding the Trucks
 

I have two trucks, well technically a truck and an SUV that I have been using as daily drivers. Both are GM s-series vehicles but they could not be more different if they tried. The pickup truck is an 88 S10 with a 5 speed and a 4 cyl engine. It has no A/C, no radio, manual windows, locks, steering and brakes. It is about as bare bones as you can get. The other vehicle is a 1998 Oldsmobile Bravada, V6, Automatic, AWD, and about as fully loaded as cars came in 98. For obvious reasons I mostly prefer to use the Bravada as much as possible but honestly it has got to be one of the most pointlessly inefficient vehicles ever.

At least if you have a sports car pulling down getting crummy mileage is understandable because it's fast, but the Bravada is not fast. Or poor mileage in a full size truck makes sense because you can haul large loads and/or large trailers, the Bravada does neither. Or in a Van at least they can carry a lot of people and stuff but alas the Bravada only seats 4 comfortably 5 if you squeeze them in there, but throw a couple car seats in the back and it isn't even an option. All things considered The Bravada is just a pig for no good reason.

Well I have been aiming on improving the fuel efficiency of both trucks but I have mainly been focusing on the Bravada since it gets driven the most. And I will be honest up front Most of the stuff that I am doing is based on the research of others because I really just don't have the time or money to try and ABA test every single modification that I have done. Hopefully though the results will show at the pump and so far for most of them they have.

Now onto the Mods!

I'll start with my S10 Pickup because, well there are less mods on it. For the S10 I already know that it is going to get fairly decent gas mileage right off the bat by virtue of the fact that it is a 4cyl, it is very light and with the 5 speed I can drive it much more efficiently. The most obvious thing that I have done was to lower it, which one, reduces drag and two, allows me to carry more momentum through corners. I have also installed a hard tonneau cover which I have seen firsthand on my old truck definitely helps the fuel efficiency. I also very recently just finished replacing the mechanical fan with an electric fan. That mod was high on my list of priorities because I knew that mechanical fan was just constantly robbing the engine of power because it did not even have a clutch it was just mounted solid to the water pump. But honestly that's about all that I have done with that truck so far other than some cosmetic stuff and normal maintenance. So far I have no idea what kind of mileage that truck gets. I just don't drive it a lot and I rarely ever put gas in it. It's crazy how long I go between fill ups, usually months.

Here are some pics before:
https://lh5.googleusercontent.com/-j...0/IMAG1142.jpg

After:
https://lh3.googleusercontent.com/-E...103_142129.jpg

Old Mechanical fan
https://lh6.googleusercontent.com/-D...915_111637.jpg
I mean who's bright idea was that?

New E-Fan, much better!
https://lh5.googleusercontent.com/-g...117_094620.jpg

And then there is the Bravada.

I have been trying lots of little things to help bring up the FE of the Bravada. I started with smaller mirrors and also lowering the suspension. And although I lowered it far less than I did my S10, the improvement in stability was still drastic. I have also swapped out the fairly aggressive All Terrain tires for some that were more street oriented and put them on a set of larger lighter wheels. Overall I lost at least 10 pounds from each wheel and tire. I also recently pulled the roof rack off and built a grill block for it. That last item is still sort of in it's trial period though as I don't know how that is going to effect the engine temps when it gets warmer. Overall with the combination of modifying the truck and modifying my driving style the Bravada has improved from an average fuel efficiency around 14.5mpg to almost 18mpg. It would probably be even better than that but traffic to and from work has been getting worse in a direct inverse proportion to the number of things that I have done to the truck. It's kind of weird.

But the mods that I have done to the Bravada I am trying my best to keep either very tasteful or easily reversible as I don't expect to keep it much longer, and I want to be able to keep the resale value at least still existent. But as long as I have it I am going to keep trying to make it better.

Before:
https://lh4.googleusercontent.com/-z...-07-180509.jpg

After:
https://lh4.googleusercontent.com/-u...118_164304.jpg

Close up of the Grill Before:
https://lh6.googleusercontent.com/-e...118_154315.jpg

...and After:
https://lh3.googleusercontent.com/-g...118_154843.jpg

I just wanted to start a thread where I could document the work that I am doing on my trucks and track the changes and hopefully positive impacts on my fuel efficiency. But if anyone has suggestions on things that I cna improve or ideas for other simple mods please feel free to throw them out there.

lowering is certainly a good start.
Have the larger rims/tires helped on the p/u?

Actually the wheels/tires in that last picture of the s10 are about the exact same OD as the stock ones. Now for what it's worth I did have some taller tires on it before but it was not really helping much because they were also considerably wider.

https://lh3.googleusercontent.com/-e...103_094655.jpg

Still I am already planning on installing a taller rear end in the truck, hopefully in the very near future. Right now it has a 3.73 and on the highway it just screams. I don't have a tach installed but at 60 on the interstate the engine has go to be turning at least 2500rpms. But I am keeping an eye out for something higher like a 3.42 or 3.23 at the local junkyards. Also for what it's worth I really want to get a tach and some other gauges hooked up too. The truck only has a speedo and a gas gauge. I would feel a lot more comfortable with a oil pressure and a coolant temp gauge installed also.

IMO, just make the Bravada ready for sale. Elbow-grease cleaning energy (undercarriage, wheelwells, etc). What driving you do (14.5 to 18 = 20%) just keep up your new average . . that's work enough. The changes look nice.

The S10 is a cool & clean little truck. Add A/C if it is to be a keeper (or a stereo or whatever critter comforts you want). At that age, worry over wiring, age-related deterioration. It's a perfect candidate for an aerolid (like JRMichler) and some super hypermiling.

A real nice start for your thread.

Ooh that E-fan is going in the wiki
I picked up about 2mpg in the city and on the highway. Wasn't expecting a city MPG improvement.

http://ecomodder.com/wiki/index.php/...m_thread_links

3.42/3.73=.916

That's less than 10%. Increasing the rear tire size (for example 28" to 31") gives a similar result. It's not 4WD is it?

Thanks for the kind words. And yeah I am not planning on doing too much more with the Bravada and most of the stuff that I have been doing are basically free mods. Even the new grill didn't cost me anything since I already had the GMC grill from my old truck and the block I made from a piece of interior plastic trim from another old project. So even that was a free mod. As far as getting it ready to sell hopefully that should just be a matter of cleaning it up on a Saturday afternoon. Depending on who I am trying to sell it to I may leave it as is or try to get it back closer to stock. But since I still have most of the original parts it is just a matter of throwing them back on the truck.

The S10 I plan on keeping pretty much forever but I doubt it is ever going to be my primary vehicle. Even though I know it is not going to be driven a lot I still like modding it to improve its mileage and drivability. I'm honestly not too worried about installing A/C or anything like that because I really love the fact that this truck is just so simple. I did install a rudimentary sound system not too long ago which is basically a small audio amplifier attached to a 3.5mm cable and some speakers in the stock dash locations. It's certainly not going to win any awards for sound quality but it works just fine for now. Other than that I'm pretty happy with the truck, I mean obviously it still needs little stuff done to it, but I love just having something to tinker on. Oh and I have already been thinking about various ways that I could build an aero lid for it. That is actually something I have been thinking about doing for a few years now. I have a few interesting ideas but they are probably just going to stay in my head for a while.


Thanks! I feel honored :) but yeah I see an e-fan as being a fairly significant mod, it really feels like I am killing lots of birds with that single stone. The e-fan is not only freeing up HP that is normally being wasted sucking air through a cold radiator but it is also allowing the engine to warm up faster and stay warmer especially in this cold weather. Also I have noticed that it allows the engine to rev up much faster which drastically improves the drivability and it is also probably going to even prolong the life of the water pump bearings. The best part is that it is just so simple that pretty much anyone who is mechanically inclined can do it. I think I have a total of about $60 wrapped up in this mod (used fan was $35 controller was $24) and I have no doubt that it can easily pay for its self. And honestly even if it didn't return a huge improvement in MPG it has already paid for its self just with the drastically improved drivability of the truck. Freeing up 4~5 Hp (I'm guessing) is a big deal when your engine only puts out around 92 to start with.

It's just 2wd and yeah, that would definitely be one way to do it. But honestly for me it would probably be cheaper to just throw a junkyard axle in it than it would be to even buy two new tires. Besides once I get the taller rear end in it I can always take it further with taller tires if I want to later. Besides, trying to get a 10% change with tires alone would be crazy for me. The tires on it right now are around 25 inches tall, so to get a 10% change I would have to go to a tire over 28" tall. Which would be absolutely huge on this truck. Also I need to be careful messing with the gear ratios because this is a small truck with a small engine but I still haul stuff with it so if I go too high on the rear end it might not have enough engine to get out of its own way when it's loaded down.

On taller wider tire:
Back in 2007 I'd had the truck for about a year so I was well aware of its MPGs and had been tracking them for a while. When I went from 235/75R15 tires to 13x10.5R15 tires I lost no fuel economy as far as I could tell.
I was not expecting that result. I was expecting to lose at least 2mpg since 2007 seemed to be the hight of the smaller thinner tire fad.

I will add that part about having $60 tied up in doing the mod also.
To add to that I noticed that my diesel cranked over faster with out the fan on there. I did the mod back in 2006, with a burned up and under sized power cable going to the starter.

My favorite thing about my Efan is how much quieter engine start up is... I am trying to use my Dodge RAM 20.5 MPG ABA testing thread in a similar fashion; to keep me honest and catalog what I'm doing... My might look into getting some wheel covers like MoonEyes, I think you did a grill block already, maybe even a tuner. My Superchips is worth another 1.5mpg...

It wouldn't be so hard to find a stand-alone transmission controller to the Bravada, then you could swap its stock engine for a Diesel and get some good mileage improvement, averaging 30MPG easily.