Conversion Van Mileage?

yamsack · Sep 8, 2011

Hey all, For all of you who own hi-top conversion vans, may I ask what kind of gas mileage you're getting on streets/highways? For me, I just got a '92 Ford E-150 hi-top conversion van and was just wondering what kind of mileage I'll be getting out of her.

Seraphim · Sep 9, 2011

We had an 88 Ford 150 conversion van - standard style conversion - and probably got abpt 18 - 20 highway. Our current RV has a HIGH camper top - with a sleeper extension over the cab - and we get 13 - 15 highway.  It's also equipped like a house, so there's a great deal of additional weight. <IMG border=0 hspace=0 alt="" align=baseline src="http://bentfalcon.files.wordpress.com/2011/04/gyrfalcon.jpg">

yamsack · Sep 9, 2011

@ blkjak   My engine is either an 8 cylinder 5.0 or 5.8.  According to the link you gave me, even without the heavy hi-top, the van only gets 11-14 miles combined mileage.  Won't the extra weight of the hi-top bring that down to below 10 miles per gallon? I better be real careful about where I'm going to drive or else the money I'd be saving by not paying rent will only go into paying for all the extra gas.  I hope I didn't make a huge mistake by buying a hi-top van.

yamsack · Sep 9, 2011

@ blkjak   Is yours a hi-top as well?  If you're getting 14 city, that's not too bad for me.  I was just concerned if it dipped below 10 city.

MK7 · Sep 10, 2011

Seraphim said:
We had an 88 Ford 150 conversion van - standard style conversion - and probably got abpt 18 - 20 highway. Our current RV has a HIGH camper top - with a sleeper extension over the cab - and we get 13 - 15 highway.  It's also equipped like a house, so there's a great deal of additional weight. <img alt="" src="http://bentfalcon.files.wordpress.com/2011/04/gyrfalcon.jpg" align="bottom" border="0" hspace="0">

Not sure how you can get such great mileage.  I would think an '88 tech van would get a little worse than something 10-20 years newer. But these newer vans w/V8's are getting nowhere near 18-20 MPG highway...and these are the non conversion vans. Conversion vans should weigh a lot more + that hightop kills at least 2 MPG.  People have claimed that just removing the roof rack off of a Chevy Astro gains about 1 MPG consistently.

MK7 · Sep 10, 2011

blkjak said:
    i am getting 14+-mpg in town and 18+- mpg hwy .... 300 miles divided by 15mpg equals 20 gallons times $3.50 per gallon equals $70.00 per week or $320 a month .... <img src="https://vanlivingforum.com/images/boards/smilies/eek.gif" align="absMiddle" border="0">

This is rough right here. $350/month can rent you a sublet room somewhere.  If you're only driving 300 miles per month then you're obviously not traveling but are just moving your van around to stay stealthy or such....and running small errands right?   I wonder if you can look for a house that its owner needs tenants to help with the mortgage and make a deal to just park at their house and maybe some use of their electricity, shower, etc.

Seraphim · Sep 10, 2011

Not sure how you can get such great mileage.  I would think an '88 tech van would get a little worse than something 10-20 years newer.

88 Ford was new when bought it and we had it for 10 years - used it for travelling around the country. I generally drive conservatively and use the cruise control. When budgeting for a trip I used 15mpg average, and my fuel bill was always considerably below budget. It wasn't a tech van, but a custom conversion: rear seats made a bed, no other camping conveniences. Made for comfortable travelling. On my RV (the one in the photo), I just fueled it yesterday and the figures came out to 12.7 mpg. Most of that was city driving though; it's been raining the past week and I haven't been commuting on the bicycle. My bug is down so I drove the RV to work. Both the 88 Ford and the RV (a 96) had/have a 350 engine. The 88 was a half ton, the RV is a one ton chassis.

MK7 · Sep 10, 2011

blkjak said:


MK7 said:

 But these newer vans w/V8's are getting nowhere near 18-20 MPG highway...and these are the non conversion vans.  

Click to expand...

i get 18mpg hwy modified .... van is smooth .... stealth ....

That sounds right. I made a mistake. Some reason I keep thinking that they should be around 15 HWY.  But 18-20 HWY is very accurate then.

i increased engine air intake ....

Is the increased engine air intake a cold air intake that routes to the bottom like a ram air or is it just a reusable conical air filter attached to the air intake hose where the stock airbox used to be?  I know that the cold air types that routes a tube down and outside of the engine bay to get cold air does work....like a ram air. But the ones where it's a conical air filter that's still inside the engine bay doesn't work b/c it's sucking in hot air from inside the bay. And sometimes the car's cooling fan causes a backwash of uneven & turbulent hot air into the air intake causing spiking to the mass air meter.

i increased engine exhaust ....

What kind of exhaust? Is it just the catback? Or is it also the H-pipe and the headers? I've had over 10 Mustangs with similar motors used in the  Ford vans except that they were the HO version that breathe much better. All of my Mustangs were modified with at least a catback and up to full exhaust (along w/heads/cam/superchargers, etc). And going with full exhaust from the headers to the tailpipe to gain power, did work, but really didn't do anything for gaining MPG b/c you lose back pressure, thus, losing a little power at lower RPM for normal driving....but gaining power at higher RPMs, when racing.  What I also did gain was a ton of noise, which was great for a Mustang...but I don't see that helping your van being stealthy. Starting up my cars, the neighbors would complain that the rumbling they made caused the old paint on their house siding to flake off.

i have a light weight build ....

It can't be lighter than what these government MPG sites list the reported MPG as being because those are completely, stock and empty vans.

i have a tuned engine ....

These MPG figures are from brand new vans, so they are well tuned as well.

MK7 · Sep 10, 2011

Seraphim said:


Not sure how you can get such great mileage.  I would think an '88 tech van would get a little worse than something 10-20 years newer.

Click to expand...

 88 Ford was new when bought it and we had it for 10 years - used it for travelling around the country. I generally drive conservatively and use the cruise control. When budgeting for a trip I used 15mpg average, and my fuel bill was always considerably below budget. It wasn't a tech van, but a custom conversion: rear seats made a bed, no other camping conveniences. Made for comfortable travelling. On my RV (the one in the photo), I just fueled it yesterday and the figures came out to 12.7 mpg. Most of that was city driving though; it's been raining the past week and I haven't been commuting on the bicycle. My bug is down so I drove the RV to work. Both the 88 Ford and the RV (a 96) had/have a 350 engine. The 88 was a half ton, the RV is a one ton chassis.

My mistake, I keep thinking that the V8 full sized vans only get 15 HWY. And I don't mean to doubt your MPG claims for no good reason. I've been researching hard to see what kind of van is good for me, mostly due to the current gas prices that's only going to get worse probably. I'm currently swaying towards an Astro Conversion AWD, but then saw your MPG numbers for a full size van w/a V8 and thought that I should rethink. I currently have a 530hp Cobra that gets 12 MPG on mandatory 93 octane gas, so it's not fun at all. This is why I'm really prying about MPG numbers. Thanks again for your help.

MK7 · Sep 10, 2011

blkjak said:
 hi .... you are talking about major changes to increase horse power ....

No, I said that I had Mustangs that were of the same level of modifications that you have....just mufflers and air intake....and later on I would add further mods. [/quote]  i did very minor changes to intake and exhaust to help gas milage a little .... [/quote] But what you did also increased power and NOISE, whether that was your goal or not.  And noise is a bad thing if you want to be stealthy for urban camping.

if i think it added 1 mpg i am okay with that ... if you do not think that i added 1 mpg i am okay with that .... blkjak ....

Well it's actually more than how you feel, b/c this thread is about MPG. People will read this and think that what you did worked w/o question or something. If they go out and have shop cut up their good working stock muffler and put on a Magnaflow(s) like you did, it's not cheap and certainly not free. Then they find out that their van is noticeably louder now too. If I were living in a van, trying to be stealthy, I would never opt for an aftermarket, high performance muffler....which is what Magnaflows are. And in general, swapping out mufflers only would gain about ZERO in terms of performance and MPG. It gains a lot of noise though, which is great for people who likes loud cars, not vandwellers. The cold air induction I would do if I were a vandweller. But it's not cheap neither. The ones that don't work, cost about $50-100 (sits in the engine bay). The ones that do work, are around $150-200 (that's routed outside of the engine bay to suck in cold air)...but I've never heard of one prefabricated for a van before...for performance cars, yes.  You'd have to make one with a conical air filter ($25-50) and clothes dryer ducting ($20-30).  There's still a  slight noise increase though. And you need to clean the air filter often b/c it's sucking in more dirt & debris. There's a definite increase in power & MPG, just not sure how much b/c it fluctuates with speed. Added benefit is that the air filter can be washed & reused, saving you $10-20/year. [/quote]

Seraphim · Sep 11, 2011

Blkjk

You can spend a lot of money trying to get insigificant gains in hp/gas mileage - and the two really don't (necessarily) equate. You can make an engine more efficient, but whether that equates to hp or mpg depends on other factors, not the smallest of which is driving mannerisms. A transmission's shift points play a major factor, as does timing, rear end ratio, etc. The Ford I mentioned above got better mileage than a work van because the components were selected for 'cruising'. A work van is generally designed for heavier cargo - torque over top speed - and while it will have a higher weight capacity it will not be as fuel efficient.

It's been my experience a lot of these hp/mpg 'improvements' do little if nothing, and I'm speaking from dyno results (and not seat of the pants dyno either lol). They're generally a waste of money and just give the purchaser a good feeling and a mod to brag about.

Find a van Which has has components designed for highway travel. Put an K&N filter in if it makes you feel better, retune the computer and shift points if you want to kick several hundred dollars into it, but making sure your tires have the proper pressure will do more for your gas mileage. Keep the cargo within the vehicles specifications. Accelerate a bit more slowly and keep your highway speeds down. Learn to drive a manual transmission and skip shift. Change the gearing of the rear end if you have a vehicle set up for towing.

Just my $.02

MK7 · Sep 13, 2011

There aren't any difference between a cargo van vs. a passenger van of the same year/model when it comes to the transmission and torque converter. And the shift points are only reprogrammed for high performance purposes, like raising it closer or into the redline. There could be a difference however in the rear end gearing that would affect MPG & performance.  However, both models would need good torque, regardless and would both also strive for good MPG to be competitive....so the cargo van wouldn't be outfitted with really low gears like 4.10:1 or something and sacrifice significant MPG. But stock for stock, the cargo van should always get the best MPG b/c it's a bare skeleton. It doesn't even have insulation.

Seraphim · Sep 14, 2011

Not that I like to be argumentative *grin* but once you take the seats out - even leaving them in - the weight difference would have little effect on the mpg, and if you're planning on insulating it anyway - it's easier to strip out what you don't want than add what you do. Granted, most of my mechanical experience has been with performance vehicles. But everything done in one direction can be done in the other.  I have no experience with diesels, but there are controllers available for them to modify the performance levels. Another factor to consider is tire pressure. You can overinflate the tires at the expense of ride comfort and tire wear. When I first got the RV I was impressed by 15 mpg hwy miles - until I checked the tire presure and found out the previous owner had them all inflated at 90 psi rather than 50/80.

MK7 · Sep 14, 2011

Seraphim said:
Not that I like to be argumentative *grin* but once you take the seats out - even leaving them in - the weight difference would have little effect on the mpg, 

Weight certainly affects MPG. Especially when you're in stop & go traffic having to constantly start the car moving from a complete stop.  And once moving, even on the highways, the weight is causing a frictional drag on the suspension, drivetrain, etc. This all affects MPG.

Granted, most of my mechanical experience has been with performance vehicles. But everything done in one direction can be done in the other.  I have no experience with diesels, but there are controllers available for them to modify the performance levels.

Are you talking about the shift points? The factory stock shift points are set at the a near optimum settings already in terms of striving for adequate torque, power, MPG and reliability. If you wanted to shift earlier (lower RPM) with an automatic, you just feather the gas pedal, lift off, and feather it down a little....it will upshift. If you wanted to get the most power, you'd floor it to activate WOT mode and it will upshift once it hits the programmed RPM deemed safe by the stock setting.  There is no need to alter the shift points for better MPG. You can however alter the shift points to RAISE the RPM over the factory stock setting to gain power (but horrible MPG). So when you floor it, it now will go to a higher RPM than stock where it will net the most power & torque.  But in order find out what this RPM is, you'd need to DYNOTUNE it on a dyno.  The software to alter these settings for my Trans Am cost $550 (HP Tuners). Dynotuning cost $400-600 for the base tune and $200-300 for any later changes. For my supercharged Cobra, it cost over $1000 for a dynotune and $400-600, each time....for changes. A dynotune will certainly help MPG b/c a good tuner will also find the optimum air/fuel ratio for the entire RPM spectrum of each gear. The stock factory has a canned tuned that leaves much on the table b/c they wouldn't spend the resource on tweaking every little thing of every single car....due to each car being different + different altitudes where it will be driven + different weather, etc... which is all affected by air/fuel ratio.  But it's still crazy to spend $1000+ on dynotuning for a stock van.  And I don't even think that they have a PCM tuner for vans.

MK7 · Oct 24, 2011

Seraphim said:
 <img alt="" src="http://bentfalcon.files.wordpress.com/2011/04/gyrfalcon.jpg" align="bottom" border="0" hspace="0">

man, that is so nice.

Seraphim · Oct 24, 2011

Transmission shift points are one factor. One electronically adjusts the tranny to shift at a particular rpm - the lower rpm the better mpg. Modern trannies are computerized as well. PCM tuners don't car what type of body the engine is in: they merely adjust the engine's PCM. Contact the manufacturer, tell them what you have, what you want, and they'll send you the tuner programmed to meet your needs.

The diesel programmers are on board and adjustable by the driver in real time. I have no experience with them.

MK7 · Oct 24, 2011

Seraphim said:
   Transmission shift points are one factor. One electronically adjusts the tranny to shift at a particular rpm - the lower rpm the better mpg. Modern trannies are computerized as well. 

Not necessarily true. If you shift to a higher gear too soon and stay there, you'll lug the engine and lose MPG....especially if you're going uphill. The stock, manufacturer setting is usually already good if MPG is the main criteria. People who adjusts the shift points, do so to increase the quickness of the car for racing by raising the rev limiter, thus bad for MPG. This is where the $400 dynotune is important as it shows exactly where the power drops off, even if the motor can still rev higher and actually lose performance + risking engine failure.

PCM tuners don't car what type of body the engine is in: they merely adjust the engine's PCM.  Contact the manufacturer, tell them what you have, what you want, and they'll send you the tuner programmed to meet your needs.

This is incorrect. PCM tuners are not available for every car type even if they share the similar, base motor. PCM tuners are developed by companies that see a potential profit in marketing such to hot rodders and not vandwellers.  And PCM tuners are certainly not available for every type of motor....just the very few that are popular among car enthusiasts.

Seraphim · Oct 25, 2011

Not necessarily true. If you shift to a higher gear too soon and stay there, you'll lug the engine and lose MPG....especially if you're going uphill.

I rather thought that was too obvious to mention. *smile* Especially to one who prefers standard transmissions.

PCM tuners are not available for every car type even if they share the similar, base motor. PCM tuners are developed by companies that see a potential profit in marketing such to hot rodders and not vandwellers.  And PCM tuners are certainly not available for every type of motor....just the very few that are popular among car enthusiasts.

In general, you are correct. But you are merely referring to products that are mass produced for the general market. The modified 400 SB in my El Camino is possibly the only configuration like it anywhere. Once I make the transition to fuel injection, I'll have to have the new system's PCM flashed to match the blue print of the engine. No company, however, will mass produce a tuner for that configuration, because they will never sell another. I will have to pay for their engineer's time to custom program a tuner to meet my needs. You can have a company do a custom tune for anything that has a PCM. You will pay for it - custom jobs are are not cheap (which is why my Elky still has a carb), and generally only used by custom engine builders. I did, however, purchase a mass-produced tuner for my stock '99 Z-28 - the LS1 engine was popular enough at the time to support the manufacture of of a tuner for that specific vehicle.I also had an LS1/M6 transmission I planned to put in a Volvo P1800E (don't ask what happened lol I tend to cry.) The PCM didn't care what kind of body the engine was wearing, it only cared about the engine and the transmission specs. So, to be accurate, your comment should read: "Mass produced PCM tuners are not available for every car type..." I doubt, however, the OP is interested in a debate on the availability of custom programming for PCMs. The possibility was mentioned in passing as a theoretical possibility, not really as a practical one. If you wish to continue the discussion, head over to LS1.com. I know they have extensive information on doing a custom flash of a PCM, though they will be specifically oriented to the LS1 engine.

MK7 · Oct 25, 2011

Seraphim said:
 I rather thought that was too obvious to mention. *smile* Especially to one who prefers standard transmissions.

You said "the lower rpm the better mpg.".  It's not true because if you go too low, you'll lug the engine.

  In general, you are correct. But you are merely referring to products that are mass produced for the general market. The modified 400 SB in my El Camino is possibly the only configuration like it anywhere. Once I make the transition to fuel injection, I'll have to have the new system's PCM flashed to match the blue print of the engine. No company, however, will mass produce a tuner for that configuration, because they will never sell another. I will have to pay for their engineer's time to custom program a tuner to meet my needs. You can have a company do a custom tune for anything that has a PCM. You will pay for it - custom jobs are are not cheap (which is why my Elky still has a carb), and generally only used by custom engine builders. 

that sounds like a piggyback chip that they burnt.

I also had an LS1/M6 transmission I planned to put in a Volvo P1800E (don't ask what happened lol I tend to cry.) The PCM didn't care what kind of body the engine was wearing, it only cared about the engine and the transmission specs. So, to be accurate, your comment should read: "Mass produced PCM tuners are not available for every car type..."

I rather thought that was too obvious to mention.

I doubt, however, the OP is interested in a debate on the availability of custom programming for PCMs. The possibility was mentioned in passing as a theoretical possibility, not really as a practical one.

Yea, this is why I first said that it cost too much and would be a waste on a van.

Seraphim · Oct 25, 2011

that sounds like a piggyback chip that they burnt.

Nope.

Conversion Van Mileage?

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