Cube Van MPG

Mrnewbie · Sep 29, 2011

Hi everybody I am new to the expediting world and just had a few questions for those of you who have been around longer. I own a 2007 GMc cube van 10k gvw(formerly penske) It gets 12 miles per gallon on the highway currently. Here are my questions first of all I am looking to do a gear swap from 4:10 to 3:55 or 3:73 would this be a good idea? Secondly I am looking into the gearvendors od unit that says it increases fuel economy by 22 to 28 percent, but its 3000 dollars upfront, do you think it will ever pay for itself fully? Lastly about those wind deflectors and air tabss do they work as well as they claim? The wind deflector claims 1 to 1.5 mpg increase and airtabs claim 4% which equalls about .5 mpg All told with these improvements and changes( using the companies math of course) I can get this van up to about 16.5 mpg does this seem possible to you guys. Thanks for any answers you can provide me

scottm4211 · Sep 29, 2011

Hi. The wind deflector will give you about 1 mpg. Well worth it. No clue on the other ideas.

Mrnewbie · Sep 29, 2011

Also can anyone give me any suggestions for a cube van wind deflector all I can find are full size truck ones or ones made for a pickup hauling an rv, do you think that type would work?

Jefferson3000 · Sep 29, 2011

The are a number of Air Tab enthusiasts on this site who will vouch for its benefits. An air deflector/shark/air scoop on the roof of the cab will certainly cut down on drag. I've even seen some small ones for the front hood.

scottm4211 · Sep 29, 2011

You can get a nose cone bubble type mounted to your box. That's what I have.

Moot · Sep 29, 2011

Mrnewbie said:
Hi everybody I am new to the expediting world and just had a few questions for those of you who have been around longer.

Is the cube van in question a single rear wheel or dual rear wheel set-up? Don't you love a person that answers a question with a question? Ooh, that was two questions!

Check with some cube van box manufacturers like Supreme, Baybridge or Rockport. They all put cab top fairings on their cubes. Most look like they come from the same source.

I think going to a 3:55 might be too steep of a gear ratio, but a 3:73 should work.

Jefferson3000 · Sep 29, 2011

Moot said:
Is the cube van in question a single rear wheel or dual rear wheel set-up? Don't you love a person that answers a question with a question? Ooh, that was two questions!

Check with some cube van box manufacturers like Supreme, Baybridge or Rockport. They all put cab top fairings on their cubes. Most look like they come from the same source.

I think going to a 3:55 might be too steep of a gear ratio, but a 3:73 should work.

I did have a question about the gear ratio, as this is an automatic. Is the gear swap even possible? If so, what you don't want to happen is to take it so far that the truck becomes sluggish.

I would definitely check with box manufacturers. A local dealer may even be able to send you in the right direction.

chefdennis · Sep 29, 2011

yes the axle ratio can be changed...355 is too high and the motor will accelerate terrible at highway speeds...the 373 is good...you can also have the ecm "flashed" for a few hundred bucks which you should do anyhow when you change the axle ratio. There is a company in San Antonio TX that will do a new ECM for you, send it to you and then you can either keep the old one or send it back and he will refund the core charge...

I looked into the Gear venders unit and yes it will pay for itself, but the axle ratio change will do a good job and doesn't cost half as much...and if you get that thing ti 16-16.5...let me know....

scottm4211 · Sep 29, 2011

I'd bet 15 mpg is the max for a DRW unit.

Mrnewbie · Sep 29, 2011

Hi guys it is a dual rear wheel sorry I forgot to mention that. I didnt think I would ever get it up to 16 mpg lol but I am hoping to be able to get around 14.5 or so as 9o percent of my loads are in the northeast and upper midwest and gas prices are still 3.70 its costing me a fortune. As far as the gear vendors unit goes this van is not equipped with overdrive and I was hoping that would be able to significantly lower my rpms both for engine life and fuel efficency. Thanks for the info on the gear swap I thought 355 was to high and was leaning towards the 3:73. I guess I will start there and see what kind of improvement it makes and go from there

chefdennis · Sep 29, 2011

NO OD???? Is it a 3 spd auto?? What motor??? I could be wrong, (it wouldn't be the 1st time, just ask any of my ex and current wives) but i am thinkin that the trans is a 4 spd and that 4th gear should be a OD....

60MPH · Sep 29, 2011

If it is a 07 it has OD you just don't see it on the stick. D is OD on a GM product. As Dennis started 3.73 would be the highest gear set you want. How fast do you drive?? I have personally driven a 06 penske 15' box truck on a 3500 gmc chassis, I got 15+ on the 4 tank fulls that I ran keeping it between 57-60mph and starting slow and driving easy with it. 12 sounds real low it either has other problems or you are trying to keep up with traffic.

60MPH · Sep 29, 2011

07 only use 2 trans in van chassis and it would either be a 4L60E or a 4L80/85E. I would think in a 3500 chassis you could only get the 80/85E. 80E for the 5.3/6.0 and the 85E with the D-max. They may even put the lil 4.8 in a 3500 with DRW but I doubt it. If it did have a 4.8L it would have the lil 60E in it which is still a OD trans.

scottm4211 · Sep 29, 2011

Push the "tow" button on the dash at 75 mph then you'll know

Mrnewbie · Sep 29, 2011

Woops sorry guys brain cramp there it is a 4 speed transmission. I just assumed since I didnt see it there wasnt one on this model. As far as how fast I am driving it I typically stay right at 60 if I go any slower around here I get lots of angry cars and tractors piling up behind me and lots of one finger salutes. On my last trip which was 450 miles I averaged exactly 12.5 miles unloaded going 60 mph.

Jefferson3000 · Sep 29, 2011

Mrnewbie said:
Woops sorry guys brain cramp there it is a 4 speed transmission. I just assumed since I didnt see it there wasnt one on this model. As far as how fast I am driving it I typically stay right at 60 if I go any slower around here I get lots of angry cars and tractors piling up behind me and lots of one finger salutes. On my last trip which was 450 miles I averaged exactly 12.5 miles unloaded going 60 mph.

MrNewbie: I sent you a private message about your truck that is off topic.

Mrnewbie · Sep 29, 2011

Responded to you Jefferson

greg334 · Sep 29, 2011

Dropping it to the 3.73 may not give you what you want, you need to weigh out the savings that a change with all the accessories are going to give you against the added fuel used. You may find that the money spent on a proper gear change with the added deflectors and such may not be worth the cost.