PappyChris
Explorer
Joined 12 years ago
User Profile
User Widgets
All Activity
Re: Wheel size upgrade.
pnichols wrote: When going down the road, the work to overcome wind resistance is not related to the diameter of the tires and/or what mechanical gear the engine is in. A vacuum gage will read the same for the same RV on the same stretch of road, at the same speed, in the same mechanical gear, and under otherwise identical conditions - one time with a smaller diameter tire, the second time with a larger diameter tire. The only difference should be slightly better gas mileage with the larger diameter tire due to less friction and (maybe) less heat loss in the engine at lower RPMs. Pnichols: My formal education in this area and 40+ years engine tuning experience would disagree with most of what you've written so there is no sense in us hashing this over anymore between us. I'm not a good debater... Only thing I wanted to find out is what size wheel people were using (other than 16.5). Don: I live on the eastern side of the Flint Hills here in Kansas. We have a lot of long straight road but quite a bit of hill climbing too. Since most of my future destinations are going to be mountain climbing in the east I am going to stick with a smaller diameter tire to help with mechanical advantage on the climbs. The minor loss in fuel economy (if any) will be acceptable when it comes to climbing those hills.562Views0likes0CommentsRe: Wheel size upgrade.
Wasn't my intention to debate tire sizes. A simple vacuum gauge can make my point. I will be using a tire in diameter close to what was originally recommended on a 16" wheel and spend my time working on the VE of the engine to increase fuel economy of my flying brick.562Views0likes0CommentsRe: Wheel size upgrade.
I would only add that increasing tire size can adversely effect fuel economy. Increasing tire size in effect loads the engine more at a given speed. It has the same effect as reducing the axle ratio which the engine sees as a higher load. All of this of course is dependent upon road and driving conditions and loading of the vehicle. I do agree that they do need higher ground clearance though. My dump pipe is crazy low. In fact it had broken the gray water tank fitting. Discovered this after I'd bought it. New water tank installed but wish I'd rerouted. I have a set of Firestone air bags in it that help a lot.562Views0likes0CommentsRe: Wheel size upgrade.
Good point on the 17" Brian (I think I knew that had I thought more). Springs and chassis become the limit. 16s are much easier to come by than 17s (on the road). Pretty sure I can get some factory wheels off a newer E350 that originally used radials. I will be researching this more. I have no intention of keeping the 16.5s. I'd wager that you can't walk into 1 in 10 tire stores and buy 16.5s in stock which is exactly (you know) what will happen with a tire failure on the road.562Views0likes0CommentsWheel size upgrade.
My (new/old) 79 Holiday Rambler 27 is still sitting on 16.5 bias ply tires (all 6 less than a year old). I intend to budget for 6 radial tires to replace them (better ride and improve fuel economy). I am looking for a consensus of opinion for my question. 16.5" tires are obsolete and I am trying to figure out if it would be better to replace with 16" wheels or go up to 17" with a lower profile tire?? Curious what others have done and opinions about their decision or what you would have done different and why. Thanks in advance!3.1KViews0likes15CommentsRe: Live and Learn -- Didn't Get my MH
Just a word of advice from someone who has bought and sold a lot of boats and a few less RVs in my life. Believe no one when purchasing. If there are no records (receipts) to back up all the claims the seller is making then do one of 2 things. What you did and walk away or if you are so inclined start with the low ball price and plan on fixing a lot of stuff. At that point the seller will likely walk away. One question you can always ask is "why are you selling it" then watch the demeanor. It will tell you a lot. They know what they own. You don't. I repair and maintain all of the systems on my equipment (marine and RV) and usually know what to expect or not. In that respect I am kinda fortunate. It's why I bought and operate at 1979 model. Good luck.488Views0likes0Comments
Groups
Motorhome Group
Join in here to discuss all things motorhomes.Jan 14, 202538,705 Posts
