Photobug
Well-known member
So no gear ratio change?
It is safe to assume with all the works it is safe to assume at least 20% or greater fuel economy loss?
Making a B+ or C Class more capable.
- Thread starter Photobug
- Start date
So no gear ratio change?
It is safe to assume with all the works it is safe to assume at least 20% or greater fuel economy loss?
BritKLR
Kapitis Indagatoris
I've played the gear/tire game.....3.73/4.10/4.56 + 15"/16"/17" + install cost = never equals significant fuel saving to pay for the gear/wheel/tire/milage chase...
It's gonna cost what it costs when rolling down the road, Just get on the road. BTW, (secret).....we've got maybe 50k and weeks at a time with two people and two cats in a Tiger, it can be done. Safe travels!
It's gonna cost what it costs when rolling down the road, Just get on the road. BTW, (secret).....we've got maybe 50k and weeks at a time with two people and two cats in a Tiger, it can be done. Safe travels!
rruff
Explorer
A gear ratio change should help your mpg, not hurt it.
Tires can definitely make a difference, but fat 35" E-rated ATMs on my truck actually have less rolling resistance than the 32" street tires that came on it. That isn't normal; but there is a big variation in rolling resistance among tires that look about the same. The new tires are Hankooks, BTW.
i went 3 “ oversize tire on my transit camper with a 2” lift and improved mpg by 1mpg. Hankook dynapro atm!!!! Love them and can’t complain about the improvement in fuel! The truck run lower rpm at hwy speed.
rruff
Explorer
Guess I'm not the only one. And guess what... they quit making that model!I'm not getting better MPG on the highway (slightly worse than before), but it is better at slower speeds <60.
Heading Out
Adventurer
No but I have had a guy blow a stop sign in front of me and he got broadsided.
I didn't plan on that, accidents happen, and nobody plans on that.
Have you never had something unexpected happen?
I have a couple of friends who run tow yards in the Mojave, and the wrecked RVs
that come into their yards are simply shocking. Most regular RV's are reduced
to a pile of match sticks and insulation.
Just sayin'
I will add, don't run dual wheels on the rear if you plan on venturing off road as duals will
pick up rocks between the tires and ruin your day.
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WRONG_WAY_DAVE
Active member
YMMV. but a good rule is anything you do to make your rig it taller, iincrease rolling resistance/ground clearence, impact aerodynamics will at a minimum, cost you 1 mpg each at steady state 60-65 mph.
Bigger tires +1 size up and 1 size wider (I assume the tire will be slightly heavier): -1 mpg (go mondo here, and expect more loss)
Raise 2-4 inches? -1mpg (go mondo here, and expect more loss)
Remove airdam, cut bumpers/add aggressive bumper for better approach or big, unconcealed winch brush guard? -1 mpg
This is exponential, so the faster you go, the worse the sum of the above will be. With big trucks/rigs, if you never go above 40-50 mph, you might see only -1 mpg at steady state.
At slow/stop go speeds, heavy weight eats MPG.
Once up to speed, rolling/wind resistance eat your MPG.
Again, YMMV
Bigger tires +1 size up and 1 size wider (I assume the tire will be slightly heavier): -1 mpg (go mondo here, and expect more loss)
Raise 2-4 inches? -1mpg (go mondo here, and expect more loss)
Remove airdam, cut bumpers/add aggressive bumper for better approach or big, unconcealed winch brush guard? -1 mpg
This is exponential, so the faster you go, the worse the sum of the above will be. With big trucks/rigs, if you never go above 40-50 mph, you might see only -1 mpg at steady state.
At slow/stop go speeds, heavy weight eats MPG.
Once up to speed, rolling/wind resistance eat your MPG.
Again, YMMV
No, it's a dually and came with stock 3.10 gears and limited slip diff......at around 10,000 lbs I average probably 9 - 9.5 on Scangauge. On flat highways I can get 10 - 10.5, hills 8 - 8.5....and dropping depending how long and steep.
I think 20% is high end decrease. When I bought the rig I was getting I think 11 maybe some more, so after all the mods my gpm is down I think 15% average drop. Whenever I fill tank I tell my self if I bought the fishing boat I wanted gas milage would be 1 - 2 gallons per mile so the RV is doing good....haha
rruff
Explorer
Physics would like a word with you...
A 2% increase in height isn't going to increase your aero drag >10%. Bigger tires do not inherently have greater rolling resistance. Only the aero drag component increases exponentially with speed. Etc.
Photobug
Well-known member
I knew this but did not factor it in, The guy who mentioned 13 going to 10 mpg also claims to be driving 80mph or higher, which would explain the 30% decrease in mpg. I tend to go the speed limit plus or minus, unless it is too high then I go under the speed limit.
I believe the RV has fairly new tires. I will try to drive the tread off this summer and look at upgrades in the fall.
willywalderbeast
Master of None
Out west/mid-west most of the highways are 75-80 mph speed limits. Try going 55-60mph when the speed limit is 75-80mph, it gets scary haha. I was disappointed with my fuel economy in the beginning but it is what it is.
Photobug
Well-known member
I love the Tiger, it is what we may end up with eventually.
Our choices would be so much easier if it were only two cats.
We have a 24 ft non-slide Class C that we bought new on the Ford E450 chassis, which was overkill because the E350 chassis is spec'd to easily carry our RV's 11,800-12,000 lb. loaded weight. What the E450 chassis gave us is a 4.56 rear differential for decent slow speed crawling, a larger diameter drive shaft, larger brake swept areas, a stronger frame to help reduce/eliminate frame twist, and sway torsion bars front and rear. Being a non-slide model, we have improved sidewall shear strength over a Class C with slides. The wheel base is 158 inches, which helps a bit to prevent high-centering.
We have no plumbing or other components (including the generator) hanging down below frame height. We also have larger than stock diameter tires for improved ground clearance of all suspension and drive components. When retracted, the side entrance door automatic step even tucks up to no lower than the sidewall lower edge.
Below is a photo of our Class C while camped off a 4X4 road in Death Valley. Note the decent rear departure angle due to the upswept design of the coach lower walls and rear storage cabinet. We take it offroad as necessary to explore and rockhound, but we do drive SLOWLY and CAREFULLY when doing it. Our longest rough road run yet has been around 25 miles each way traveling 7-10 MPH to and from an area in the Central Oregon desert.
We have no plumbing or other components (including the generator) hanging down below frame height. We also have larger than stock diameter tires for improved ground clearance of all suspension and drive components. When retracted, the side entrance door automatic step even tucks up to no lower than the sidewall lower edge.
Below is a photo of our Class C while camped off a 4X4 road in Death Valley. Note the decent rear departure angle due to the upswept design of the coach lower walls and rear storage cabinet. We take it offroad as necessary to explore and rockhound, but we do drive SLOWLY and CAREFULLY when doing it. Our longest rough road run yet has been around 25 miles each way traveling 7-10 MPH to and from an area in the Central Oregon desert.
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Photobug
Well-known member
.
Tell me about your Awning. We have been looking for one for our truck but now need to find one that works for our RV. We don't need any fancy features (electric and such) but want something sturdy to withstand some offroading.
Our awning is just the simple rugged stock manually operated one that Winnebago installed in 2005.
Once I learned how to do it, there's nothing to putting it up or down quickly. It's very strongly supported via it's triangular structure when set up. It's two lower legs portion of the triangle at each front end - that normally attach down near the bottom of the coach wall - can even be dropped down to the ground and anchored with ground spikes. Some time ago, I bought and added an anti-unfurl lock to keep it from ever unfurling when traveling down the road in high open country crosswinds ... which we saw happen once with our friends Class C when following behind them in high winds.
I don't trust automatic awnings because their triangular support structure is smaller and looks more flimsy ... and I don't like to rely on their automatic mechanism to always support well or operate correctly if high wind gusts unexpectedly occur when camped ... or even always mechanically work when setting up camp or breaking camp.
For camping On The Far Side of Beyond with an RV ... equipment reliability via K.I.S.S. (Keep It Simple Stupid) is priority number 2. Personal health and rescue capability is probably priority number 1.
Once I learned how to do it, there's nothing to putting it up or down quickly. It's very strongly supported via it's triangular structure when set up. It's two lower legs portion of the triangle at each front end - that normally attach down near the bottom of the coach wall - can even be dropped down to the ground and anchored with ground spikes. Some time ago, I bought and added an anti-unfurl lock to keep it from ever unfurling when traveling down the road in high open country crosswinds ... which we saw happen once with our friends Class C when following behind them in high winds.
I don't trust automatic awnings because their triangular support structure is smaller and looks more flimsy ... and I don't like to rely on their automatic mechanism to always support well or operate correctly if high wind gusts unexpectedly occur when camped ... or even always mechanically work when setting up camp or breaking camp.
For camping On The Far Side of Beyond with an RV ... equipment reliability via K.I.S.S. (Keep It Simple Stupid) is priority number 2. Personal health and rescue capability is probably priority number 1.