From V6 To 4 Cylinder

[Toobigboat2014]

I know this might be a dumb question. But has anyone ever converted their v6 to the bullet proof 4 banger?

I recent bought a 1993 seabreeze and wife is pretty upset due to the fact that our rig gets no where near the 20mpg that people rave about.

So here is food for thought, I found a 1988 toyota with only 43k miles, that has been total, was thinking about buying the engine and tranny for $800.

Anyone know how much it's going to cost to do the transplant?

Our plan it to travel 12000 miles this summer around the country and visit 25 major cities. Wife said it ain't gonna happen if I don't do something about the mpg. Just bought a load of air tabs hopefully that will help. So our goal is to get at lease 15-17 mpg driving 60mph. Is that realist?

[fred heath]

You can do anything if your pockets are deep enough.

The best way to spend your $800.00 is to get your rig in the best possible mechanical shape you can.

Forget 20mpg. That is not going to happen.

12000 miles at 10mpg x$3.75 gl for gas will cost you $4500.00

12000 miles at 15mpg x $3.75 for gas will cost $3000.00.

For a difference of $1500.00 I'd spend the money getting your existing rig to that 15mpg. number.

[Derek up North]

The biggest fuel savings are usually obtained by adjusting the nut behind the wheel. Air Tabs, not so much, IMHO.

[Toobigboat2014]

I'm planning on reducing what ever weight I can. Also is it better to have a super light weigh trailer to carry our heavy loads, instead of packin it all in the mh . I wonder if that will increase our mpg ?

I been reading a lot about the air tabs. Gonna try it and see for myself.

[MontanaChinook]

You could spend $1,000 doing the swap, then have a bunch of things to fix on this transplanted engine after that, depending on what shape it's in...

Unfortunately...it sounds like you should have done your homework before buying.

The swap involves wiring harness and computer, and possibly different motor and transmission mount locations.

Ask a shop if they'd even do this (many won't do fabrication, only stock work), and what it will cost. Then calculate the difference in fuel mileage. See how many tens or hundreds of thousands of miles it will take getting 4-5 mpg better in the 4 cylinder to recoup the cost of the swap. My guess is that you will never make up the cost of the swap with the possible savings in fuel costs.

[MontanaChinook]

I think any weight directly over the chassis is going to be better than weight you're pulling behind you on a trailer, for gas mileage.

[MontanaChinook]

And yes, the only people I've EVER seen "rave" about 20mpg are people selling their rv.

[Maineah]

Different wiring not a simple project. 20 MPG nope, 50 mph max 18' stick shift old one maybe close with a tail wind in the flat fields of Kansas. The mileage all ways goes up when it's time to sell. 15 is possible but 13-14 is more like it.

I'm planning on reducing what ever weight I can. Also is it better to have a super light weigh trailer to carry our heavy loads, instead of packin it all in the mh . I wonder if that will increase our mpg ?

I been reading a lot about the air tabs. Gonna try it and see for myself.

Not too likely you still have to heft the load up hill gravity is relentless.

[WME]

FWIW 22re, auto, 2people, loaded weight 6400lb. 3500 mi, 13,7 mpg@ 60-65 mph.

Before doing anything rash, give yours a full tune up and go for a weekend drive @ 60 mph and see what you get for mpg. A trailer adds drag reducing mpg

P.S. 26ft class A with 7.4L Vortec, 3people, 12,500 lb, 6400 mi, 10 mpg @55-60 mph. So 3.7mpg gas guzzler "tax", but 2x the room

[MontanaChinook]

Don't get discouraged though!

I know you're getting shot down left & right here on some ideas...but you'll learn quickly. As was mentioned in your first post about mileage, you would have been better off if you found a community like this and started asking questions before buying, but it's water under the bridge now.

I agree that the best advice is to bring it to a good honest mechanic, and have them look it over and see what it needs. You can even come back here with the list of what needs to be done and ask questions, before you let them do any of the work. Then getting the stuff done which needs to be done, and driving it at more like 55-60, and see how it does then. It is nice to have the V6 for that little bit of extra power.

[stamar]

Our unofficial estimate is that this swap will give you 1 to 2 mpg in a toyhome

I estimate a five speed swap will do a little better and be cheaper

If you have an engine swap budget throw in a 3rz from a modern tacomA

[fred heath]

A little historical data. In 1973 the U.S. speed limit was set at 55mph. This lasted until 1987.

Toyota, designed its engine and drivetrain to achieve maximum power and economy at this speed.

Taking an older toy above this limit will have a negative impact on mileage.

If you stay 55 and under, you will see the best bang for your buck!

[toyohome]

Fred,

I never thought of it in those terms. Your comments are the best yet! I've been frustrated over the mileage question and keeping this info in mind will get me the best mileage I can get. I keep my Toyohome in tip top tune.

Other's comments are great and I agree, a swap sounds like a an expensive and problem prone effort for minimal, if any better results.

[Bob C]

I have an '88 Escaper. 20', 4 cyl, automatic. Our traveling weight is just right at 6000 lbs. I drive 55-60 mph and forget about flying up the hills. I get 13-14 mpg consistantly and occassionally get 15 mpg. With a 30 mph headwind going across South Dakota I once got 11.5 mpg.

The trailer will definitly add drag. Keep the weight down and drive slower. You may want to drive with empty water tanks to loose a couple of pounds.

I wish people would knock off the crazy mpg claims.

[fred heath]

Just to set the record straight my mileage claims are completely accurate.

1. I have no intention of ever selling my mh.

2. My vehicle is 16' in length, 6'10" in height (less wind drag), carbureted, desmogged, no cat, and weighs 4200 lbs.

I kept a very accurate road log on my recent 1800 mile road trip. My rig averaged between 22-24 mpg for the entire trip. 16-18 mpg in town.

I realize larger mh's will get less mileage,but I'm tired of hearing how 20mpg is dreaming.

My vehicle is also a daily driver. I tweek the fuel/air for maximum mpg.

One advantage to the older homes is you have no computer dictating your engine performance.

[MontanaChinook]

20mpg is dreaming for anything other than Chinooks, the shortest Sunraders, and all the other miscellaneous extremely small motorhomes.

My Chinook easily gets 20mpg. But we're in the minority here, only a side note, really. 90%, to completely make up a number, of the motorhomes on this site (and out in the world) are much bigger than ours.

The motorhome we're talking about in this thread is not going to get 20mpg except driving downhill with a tailwind.

[fred heath]

20mpg is dreaming for anything other than Chinooks, the shortest Sunraders, and all the other miscellaneous extremely small motorhomes.

My Chinook easily gets 20mpg. But we're in the minority here, only a side note, really. 90%, to completely make up a number, of the motorhomes on this site (and out in the world) are much bigger than ours.

The motorhome we're talking about in this thread is not going to get 20mpg except driving downhill with a tailwind.

I agree. I stated the same opinion earlier in this thread. If he can get 13-14 he'll be doing very well.

[WME]

My Escaper averaged 13.7 mpg over a 3000+mi trip. When I was selling it I said it would get 13-15mpg, I lost a buyer to some one who was selling a Dolphin in the next city over that "got 20mpg". I often wonder what the buyer though of things later.

I once got 21mpg when touring Yellowstone @35mph, maybe I should of just advertised 21mpg.

[Derek up North]

I once got 21mpg when touring Yellowstone @35mph, maybe I should of just advertised 21mpg.

I'm sure many Sellers would take the opportunity to advertise "... up to 21mpg" or "... over 20mpg"!

[stamar]

Ive sold a lot of cars.

a lot of buyers have asked me what the gas mileage is they honestly having no idea

The orign of the toyota motorhome gas mileage is there are no epa numbers to go by just the trucks. I think the trucks got 22 mpg.

I think i have seen craigslist ads linking to the epa numbers of a toyota ickup.

[chefdave]

Hi

Very good points made in all above posts. usually when i go to buy a new car to me i look at urban mpg. this hopefully will give me worse mpg figure that i will get and if that figure is acceptable to me then its not a reason not to look at car. been looking at motorhome mags in UK and modern up to date ones with diesel engines are lucky to see 30mpg (imperial). That gives food for thought. getting 20mpg imperial on a 24 year old motorhome doesn't seem so bad.

[FredNewell]

1984 Dolphin 4 cyl stick. ~68k miles. Several 3500 mile trips including mountains, flat land, tailwinds, headwinds, cross winds, and my impatience.

When in CA on I-5 I tend to stand on the gas pedal and do 70mph.

I have no complaints about the power or performance on hills.

I burn approx 44 gallons per day if I'm trying to make 600 to 700 miles per day, which is too far, but I do it. That's data from my mileage log.

Go slow and get 14 - 15. Go fast and get 12.

The sweet spot seems to be 63 mph, for me.

Average over 7000 miles was 13.5. That takes into account the size of the Hankook tires that add an error to the odometer. The Garmin gives correct miles, the odometer is off 5% with the new tires. BTW, truckers tires give best mpg after they have 40,000 miles according to Bridgestone and Michellin - just thought I'd add that. New tires cost a percent of the mpg. Tire pressure counts too.

Tire pressure correct. Good tune-up. Fresh lube throughout. Cool weather. Roof air removed. Lowest octane regular at the pumps. Cheapest I can get. Burns no oil - dip stick constant over 3000 miles.

Once on a single tank, I got 20 mpg on a multiple round trip at 5000' elevation, Jacks Valley Road between Genoa NV and the edge of Carson City. Daily commute to Starbucks from the time share for a week. Cold weather, 45 mph tops. Drove hypermile style.

So... for budgeting a trip, I figure 25 cents per mile for fuel, with prices where they are right now.

In conclusion - going to a 4 banger would pay off if it were me.Correction... Would not pay off... Edited!

Edited February 13, 2014 by FredNewell

[MontanaChinook]

I like your post.

But I'm not sure about your conclusion!

We'd have to find out what the materials and swap would cost. Then, assuming everything is running perfectly on the swapped engine and it needs no work, find the mileage difference between 6 and 4 cylinders, and calculate how many miles he'd have to drive to start saving money.

My opinion: if someone gives you a 22re for free, in great mechanical shape with low miles, and you can do ALL the swap work yourself, not paying a mechanic one dime, this swap is something to consider, but still comes down more to preference than anything.

Ask a mechanic how many hours they'll charge for taking an engine out, putting another in, stripping each wiring harness and matching what goes where from each engine. Then either swapping transmissions also, or fabricating an adapter plate for the 4 cylinder to mate up with the v6 transmission (best option since it's a stronger tranny). I'm going on what I know of manual trannies. Not sure with autos.

I cannot imagine this costing less than $2,000. How many miles, at 2-3mpg difference, will it take to make your money back and come out ahead?

I'm not saying this isn't doable. People do crazy swaps all day long all the time. But they're doing the work themselves, and they're doing it for more power, or to upgrade to a more modern engine. If the reason for spending $2,000 is to SAVE MONEY, you really need to reevaluate.

[fred heath]

I agree with Montana.

[linda s]

I don't know how paying for 4 banger conversion would pay off when you can get those same mileage figures with a v6.

Linda S

[chefdave]

The only reason i can think of for engine swap is the engine needs a rebuild. on yotatech they recommend swapping 3.0 to 3.4 as it is almost abolt in swap. more hp more torque and better mpg. which i think would be a better swap than 4 cylinder due to weight of motorhomes.

[FredNewell]

Would it be difficult to sell if converted to 4 cyl? I tend to shy away from vehicles that are not "factory". That way I have a clean slate to create my own issues.

[MontanaChinook]

It would make it harder. If I find out that a vehicle I'm thinking about buying has been heavily modified by the previous owner, I'm definitely a little wary. There's so much shoddy work out there.

But, I almost never think of resale value when I do things to my vehicles...

[WME]

We're mostly beating a dead horse here, the original poster has since posted else where that his Toy failed smog and because of shorted O2 sensors.

[MontanaChinook]

But isn't it fun, still?

I'll agree, there is a tendency on sites like this for someone new to come along and ask a sometimes very simple question, and suddenly there's a 10 page debate and the OP is long gone...

But I think this kind of question comes up often enough...maybe someday if someone actually uses the search function we can avoid going over this again.

[chefdave]

Hi

resale value will go on laws of supply and demand. toys in uk number single digits. prices go from £2000 up to £10000. Price does not dictate condition. last confirmed sale price (money paid) was £5500 for a 4 cyl on an 85 year. everyone in UK believe they are worth £10000. If you convert toy keep receipts of all work done. mine came in box with everything from 1989. Lpg checks repairs radio etc etc and every manual for all items and upgrades (better radio and airbags). Service records and same tyres fitted all round usually mean its been looked after.

[WME]

Ok so just for fun. My 26ft Class A will get 10mpg at Toyota speeds. It has a 496 CID V-8 with a 4 speed auto, weighs 12,000 lb. It turns about 2100rpm at 65 mph.

What sort of mpg do you think a Toy MH would get with that engine in it? And how much would it tow ?

[MontanaChinook]

See that's the thing!

If you put a powerful, fairly economic engine in these little things, it can actually get better mileage, because it isn't working very hard.

My dad got me into Toyotas. He had an 86 4x4 when I was a kid. 4 cylinder. He says he got the same mileage as the Toyota when he bought a Chevy Silverado, with a v8.

But it depends on the engine. I won't pretend to know I much about engines, but my friend has a full size Dodge diesel. It only gets around 10mpg. But the nice thing about it is that it gets 10mpg whether it's empty or it's towing a huge trailer. So...that engine in my Chinook would still only get 10mpg. But the POWER!

Anyway, I'll bet there's just the "right" engine out there that would give our RVs a heck of a lot more power, while still getting in the 15mpg range. Wonder what it is? For me, though, I'll stick with the simple, efficient, reliable Toyota engine, and drive slow.

But as far as towing..of course as you know that's limited by more than just engine power.

[DanAatTheCape]

I think the concept of redesigning one of these units is not logical. Even if it all goes well (and there are many ways that it won't), you will have a unit that will have a lower resale value.

If you really really want a 4 cylinder I recommend you buy one.

BTW, these cylinders are quite reliable.

[fred heath]

What people seem to forget is the toyota drivetrain was engineered to be very economical.

The manufactures added body weight to the chassis that it was never designed to carry. For these units to last as long as they have shows a pretty durable drivetrain. I'm not sure how many US manufactured small pickup cab and chassis would do as well.