The truth and facts about noise level in gas RV's vs DP's..

[Coma]

Originally Posted by Algonquin

Technically, Torque is not a force, but the result of a force acting perpendicularly at a given distance. Hence the units are in pound-feet. For example, 10 pounds acting at a distance of 1 foot would produce 10 pound-feet of torque.

Agreed. Where the rubber meets the road is where the force is applied. A better definition would be T= F X r X sin(theta).

What is Torque? - Definition, Equation & Calculation - Video & Lesson Transcript | Study.com

[ernest917]

No doubt both gas and diesel noise levels are both acceptable on flat terrain.... No way anyone can convince me that they are anywhere close to the same climbing a 6%-7% grade.... Did it in a gasser and now do it in a diesel - hated the noise of the gasser; love the lack of noise in my diesel....

[stepside454]

I'm sure a diesel makes less noise on a grade . My point is the noise had been as bad as some make it out to be.

[Timon]

Everyone keeps calling this diesel verses gas but it's really front verses rear engine issue. Side by side a Diesel engine is just, if not more, noisy as a gas engine. It's all about engine placement and how well the manufacture insulates the engine compartment.

A FRED coach is going to be just as noisy as a gas and maybe even more so. A pusher will be quieter than any front engine if only due to the distance the passengers are from the engine but if someone was sleeping in the rear of a pusher it's going to be noisier.

So I have no doubt that it's easier to insulate the engine when it at the rear of the coach but that's not to say and engine can't be well insulated in the front as well.

The bottom line is this is a front/rear engine issue not a diesel/gas issue. It's also an even bigger insulation issue. Manufactures need to do a much better job in insulation the engine compartment on front engine coaches from the passenger compartment. If they can do it on cars they ca do it on a Class A coach.

BTW, I for one would love to see some gas coaches, such as the Thor Outlaw, have a 6.7l diesel option but not if the manufacture can't do a good insulation package.

[CampDaven]

Thor did a GRAND sound insulation job on the Serrano FRED


Dave and Nola, RV Mutants

[DrDaveMA]

Originally Posted by Timon

Everyone keeps calling this diesel verses gas but it's really front verses rear engine issue. Side by side a Diesel engine is just, if not more, noisy as a gas engine. It's all about engine placement and how well the manufacture insulates the engine compartment.



A FRED coach is going to be just as noisy as a gas and maybe even more so. A pusher will be quieter than any front engine if only due to the distance the passengers are from the engine but if someone was sleeping in the rear of a pusher it's going to be noisier.



So I have no doubt that it's easier to insulate the engine when it at the rear of the coach but that's not to say and engine can't be well insulated in the front as well.



The bottom line is this is a front/rear engine issue not a diesel/gas issue. It's also an even bigger insulation issue. Manufactures need to do a much better job in insulation the engine compartment on front engine coaches from the passenger compartment. If they can do it on cars they ca do it on a Class A coach.



BTW, I for one would love to see some gas coaches, such as the Thor Outlaw, have a 6.7l diesel option but not if the manufacture can't do a good insulation package.

I agree completely, the real question here is, if the engine is 2 feet or 35+ feet from the drivers ear, which will be less noisy? Simple physics tells us the one 35+ feet away. If you want to measure the noise level in the bedroom that is another thread and unless you put seat belts in that bed, none of the coaches is designed to be driven that way making it irrelevant data.

The turbos put on many diesels does create more noise at a high frequency, but since it is "way back there" it is not as loud to the drivers ear.

Another VERY unscientific observation from me, I hear a lot of MH owners adding insulation to their front engine rigs, I am sure someone will prove me wrong, but I have never heard of someone adding insulation to a rear engine coach, unless it was for thermal insulation.

[Timon]

Originally Posted by DrDaveMA

I agree completely, the real question here is, if the engine is 2 feet or 35+ feet from the drivers ear, which will be less noisy? Simple physics tells us the one 35+ feet away...

Just for a reference using your example of a 33' difference it accounts for a sound level difference of -24.86dB.

Every 3dB is 1/2 the sound pressure level or put another way every 10dB is 1/10 the level. That's about 1/256th of the original level.

BTW, to the ear it won't sound like it's that much. If you want an idea on how much that is and you have a AV Receiver that displays the volume in dB play something at 0dB then play it again at -24dB. You will find it interesting.

[DrDaveMA]

Originally Posted by Timon

Everyone keeps calling this diesel verses gas but it's really front verses rear engine issue. Side by side a Diesel engine is just, if not more, noisy as a gas engine. It's all about engine placement and how well the manufacture insulates the engine compartment.



A FRED coach is going to be just as noisy as a gas and maybe even more so. A pusher will be quieter than any front engine if only due to the distance the passengers are from the engine but if someone was sleeping in the rear of a pusher it's going to be noisier.



So I have no doubt that it's easier to insulate the engine when it at the rear of the coach but that's not to say and engine can't be well insulated in the front as well.



The bottom line is this is a front/rear engine issue not a diesel/gas issue. It's also an even bigger insulation issue. Manufactures need to do a much better job in insulation the engine compartment on front engine coaches from the passenger compartment. If they can do it on cars they ca do it on a Class A coach.



BTW, I for one would love to see some gas coaches, such as the Thor Outlaw, have a 6.7l diesel option but not if the manufacture can't do a good insulation package.

I agree completely, the real question here is, if the engine is 2 feet or 35+ feet from the drivers ear, which will be less noisy? Simple physics tells us the one 35+ feet away. If you want to measure the noise level in the bedroom that is another thread and unless you put seat belts in that bed, none of the coaches is designed to be driven that way making it irrelevant data.

The turbos put on many diesels does create more noise at a high frequency, but since it is "way back there" it is not as loud to the drivers ear.

Another VERY unscientific observation from me, I hear a lot of MH owners adding insulation to their front engine rigs, I am sure someone will prove me wrong, but I have never heard of someone adding insulation to a rear engine coach, unless it was for thermal insulation.

[WeBRVing]

Originally Posted by ernest917

No doubt both gas and diesel noise levels are both acceptable on flat terrain.... No way anyone can convince me that they are anywhere close to the same climbing a 6%-7% grade.... Did it in a gasser and now do it in a diesel - hated the noise of the gasser; love the lack of noise in my diesel....

The point gas owners are trying to make is that the noise level in the driver / passenger seats isn't as bad as some folks make it out to be.
As I, and others, have posted before, wifey and I converse in a normal tone of voice, while pulling a 6-7% grade. With the radio on.
Is our coach as quiet as a DP? No, but we don't have to yell at each other either, which seems to be the misconception here.

[Scarab0088]

Well said

[WILDEBILL308]

I agree. To those who have gas coaches and complain they are two noisey, Why didn't you notice this before you bought it? Ore are you one of those who bought a coach without a good test drive? Didn't you notice it was loud when you floored it to get up to speed getting on the freeway? Now that you have bought it quit whining and add some insulation. There are several sources for sound deadening insulation.
Or you can pay me and my team to come do the work.
Bill

[Fancy Free]

You are first to state you drive as I do, by matching engine torque curve to power needs. Anything over 4,000 rpm, regardless of HP peak curve, is just spinning with no power. By using throttle to manage shift points, I try and keep my rpm between 3,200-3,700 on most grades (I do not have the 5-Star tune or other enhancements, pure stock v10). I have yet to find uphill east of the Mississippi I can't maintain at least 50mph in a 34-ft coach. Good enough for me, at least until next year when we try the Rockies! 😏

[DrDaveMA]

Originally Posted by WeBRVing

The point gas owners are trying to make is that the noise level in the driver / passenger seats isn't as bad as some folks make it out to be.
As I, and others, have posted before, wifey and I converse in a normal tone of voice, while pulling a 6-7% grade. With the radio on.
Is our coach as quiet as a DP? No, but we don't have to yell at each other either, which seems to be the misconception here.

No doubt there are both gas and diesel pusher MH's that are quieter than others but realize there are also those that are noisier than others, not ALL MH's are made the same. I am sure that over the years manufacturers have improved the sound insulation and will get better in the years to come, automobile manufacturers have. The issue here is that in years past as a group gasser have been noisier than DP's. I have had both and moved from a 2002 Fleetwood Southwind gasser to a 2005 Alpine DP because on a trip from Boston to San Francisco my wife and I had to yell at each other to be heard while we were crossing the Rockies on I-40 in New Mexico and Arizona. This is NOT scientifically gathered data, it is actuality. We have since crossed the Rockies 5 times in our DP and have not had to raise our voices. Will everyone's experience be the same, no, this has been ours. Does that mean one coach is better than another for everyone, again, no, we each need to make our own decisions based upon our own situation, visit your dealer, take a test drive under conditions that are correct for you, the way and terrain you drive, then make your own decision. There is no one answer that fits all.

[WeBRVing]

Originally Posted by DrDaveMA

No doubt there are both gas and diesel pusher MH's that are quieter than others but realize there are also those that are noisier than others, not ALL MH's are made the same. I am sure that over the years manufacturers have improved the sound insulation and will get better in the years to come, automobile manufacturers have. The issue here is that in years past as a group gasser have been noisier than DP's. I have had both and moved from a 2002 Fleetwood Southwind gasser to a 2005 Alpine DP because on a trip from Boston to San Francisco my wife and I had to yell at each other to be heard while we were crossing the Rockies on I-40 in New Mexico and Arizona. This is NOT scientifically gathered data, it is actuality. We have since crossed the Rockies 5 times in our DP and have not had to raise our voices. Will everyone's experience be the same, no, this has been ours. Does that mean one coach is better than another for everyone, again, no, we each need to make our own decisions based upon our own situation, visit your dealer, take a test drive under conditions that are correct for you, the way and terrain you drive, then make your own decision. There is no one answer that fits all.

Well, I live in AZ and I was born and raised in NM. The only terrain I drive in is mountainous, 4000 feet or higher.
As I, and others have posted, normal conversation in these conditions. 2002 vs 2013, that's 11 years of advancement. Not really fair to compare a 2002 gas coach to a 2013 gas coach. I'm willing to bet that a 2013 DP is much quieter than a 2002 DP.