ANYONE KNOW THE REASON WHY??

[treedoc]

Jim. Have you ever considered changing your rear gears to a higher gear for better fuel mileage? Rick

[merle&louise]

treedoc,

Changing the rear gears ! How much better mileage would the Prevost get ?

[treedoc]

Tuga That would depend on the gear ratio. I changed the rear gears in one of my work trucks. I needed a lower gear for starting power on hills and had 7 choices! If a 8v is getting 5mpg and you could increase 1mpg that would be a increase of 20%. It would interesting to find out if someone has done a gear change and the mileage increase. Rick

[Orren Zook]

Have you ever considered changing your rear gears to a higher gear for better fuel mileage?

Don't forget, that since our engines are in the rear of the coach, the ring & pinion in a bus application turn opposite to those on OTR trucks. When I looked into the feasibility of making this gear change earlier this year there were limited ratios available and the prices I was quoted were pretty high.

[Steve Bennett]

Jim, I would have to check to see what the ratio is in our coach. We typically run @ 68 MPH, when outside of california and are turning about 1,800 RPM. I am getting between 5.5-6.0 MPG at those speeds. Ray Davis is coming out to plug his new I-Pad reader in our coach soon, so we will be able to give you some additional info. Our coach has the injectors & turbo for a 500HP application, but we have the DDEC set at 450H.P. We see peak boost of about 24 LBS, and 1,000 degrees on the EGT @ lower elevations. We have to be careful @ using full throttle at the higher altitudes, as the DDEC over fuels the engine, and we can see elevated exhaust temps.

[Coloradobus]

Just re-checked our build sheet. I have errored. We have a 3.58 rear ratio nota 3.56. There was 2 choices in 1992 for rear gear ratio, and the box for 3.58 has been checked. There other choice was 3.73.
When our speedo says 62, our GPS says 64. At this speed, our RPM says 2050-2100. At 75 on the speedo, the tach says 2300. In 4th gear, speedo is at 57, tach at 2200. We don't know what our top speed is. Guess I need to run it out. I thought 75mph at 2300 RPM was fast enough when I did that experiment. We don't generally travel any faster than the 62 on speedo/64 mph on gps
As a 1992 shell, we have the DD rated 500 hp 8V. We climb hills pretty easy and the pyros don't get too excited,.. Going to towards Breckenridge up I-70 outside of Golden, Colorado on the steep grade, we are in 2nd gear doing around 35-37, pyros at 1000 degrees, radiator stays happy at 185. Even in 2nd at the Eisenhour Tunnels, the pyros don't heat too badly, at 30mph they are at 1100 and radiator doesn't go over 190 degrees. This summer, climbing hills in Missouri no OTR, radiator was at 195 with pyros at 1000-1050 in 3rd gear with outside temps in the 110-115 range
The coach's radiator fan has been changed out from the metal one to one with 9 plastic blades.
Going up the Baker grade on I-15 eastbound in 4th to 3rd gear, we can easly keep the radiator at 185-190 with the pyros at about 975-1050. These measurements are towing 5700 lbs of Lexus.

[mike kerley]

JIm, our 93 runs at 62 MPH at 1750 RPM. We normally stay in that range with 8" to 10" of boost. Our tach does not allways correct as fast as it should, but its old....For fuel economy, I watch the boost presure more than anything, when its up at 10 or above on cruise, I'm either fighting a head wind, on an incline or have the brakes set on the toad... My best economy comes at about 8" boost and 62/1750. I'll do 5.5 to 6.0 pulling a Jeep Commander loaded with "stuff".. Not sure what gearing we have.

[Coloradobus]

Mike, I found from Elgin Prevost-Roger that they can send the entire build sheets for each of our coaches. From handwritten notes to sheets with boces to check for options.
I discovered on our sheets that our coach and I will assume all shells order by Beaver Coach have the "Astral Window" frames in the ceiling even with the 2nd and 3rd Le Mirage side window.
Notes state not to cut the metal in the roof for the windows. So I would assume Beaver did this as an option for customer. We have identified only 4 Beaver Busses so far that have the ceiling windows in the salon.,

[Coloradobus]

These speeds were judged from the GPS, not the Speedo. The only Speedo reading that was same as GPS was at 70 mph. The rest were 2-3 miles slower.

Here's the poop from our test run out on the plains east of Denver with little wind.
1ST gear topped out at 2500 RPM at 28 mph
2nd gear topped out at 2500 RPM at 39 mph
3rd gear topped out at 2500 RPM at 50 mph
4th gear topped out at 2500 RPM at 62 mph
5th gear Topped out at 2480 RPM at 78 mph

At 60 mph at 1950 RMM Boost was 5
At 65 mph at 2075 RPM Boost was 6
At 70 mph 2220 RPM Boost was 7
At 75 mph 2390 RPM Boost was 9-10 a little wind/hill
At 76 mph 2420RPM topped out Boost was

[Coloradobus]

To get back on topic, the Ford Ranger best suits our need for both work and play for its size. For comfort, the seat works well with my back issues. So, does anyone have any ideas or knowledge why the Ranger 4X4 with manual stick, has a speed restriciton of 55 mph with no distance limits. Is it a liability for Ford, or is there a mechanical reason. We haven't bought one yet, and other small trucks just don't work for my back. A Ranger is our ONLY consideration for a work/play truck, mostly work, but if we can tow it, we may. Otherwise, we will sink money into our old Chevy work truck we already own and spruce it up.