Tire size recommendation for Dodge 2500 diesel with Alaskan Camper?
#1
Posted 10 January 2011 - 03:38 PM
Happy 2011!
Planning a tire upgrade in the Spring.
Truck is now fitted with 6-7 year old 245/75/R16 range E tires. Some cracking gives me concern, so I'll get new trucks on the truck (96 Dodge 3/4 ton with helper springs and sway bar in the back) before heading very far with the Alaskan.
I'm debating on whether to stick with the stock tire size (245/75) or going up a bit (say, 265/75 or 285/75). One reason to consider going up is to get a taller tire which would lower rpm's a bit on the highway (have 4.10 gearing), and they are also a bit wider so have greater load capacity per tire (3400 vs 3040 pounds). One concern of higher tires (33 vs 30.5 in) is possibly more trouble jacking the camper onto the truck...
Any suggestions? Is 3040 pounds per wheel sufficient capacity in a range E tire to support the weight of a 10foot NCO Alaskan?
Thanks,
--Robert
#2
Posted 10 January 2011 - 04:46 PM
#3
Posted 10 January 2011 - 06:17 PM
From Baja to the Arctic and all places between!
www.generubinaudio.com
Dodge 4x4 2500 Cummins, 6 spd manual, ATC Ocelot Shell. Tesla Model S, 85KWH, 2018 Tesla Model 3 (3 of them!!)
#4
Posted 14 January 2011 - 04:06 AM
I use 285/75/17 on factory steel wheels on my 2006 Dodge 4x4. No problem at all mounting the camper, nor jacking it off With your axle ratio, and especially if you have a diesel, you could use some lower rpm's! The difference between D rated and E rated is not necessarily weight carrying capacity but more precisely air pressure capacity. The D's are 65 pounds max, the E's are 85 pounds max.
Sorry, but I very strongly disagree with you about D vs E tire.
I went to a D tire because the 285 was rated the same as the 265 E rated tire I had. Truck ran fine empty. Treadwright tires were very good in snow and rain. Then I mounted Alaskan in spring. I knew I had a problem just going out of the driveway. The tires just didn't have the same capacity. I wouldn't even let the wife drive, the truck felt so squiriely. Had a very stressful trip to FL from WI.
Didn't want to spend the money, but put Goodyear 265 E rated tires on. Big difference. I had read about the difference between E and D even though rated the same, but didn't listen. Putting an Alaskan on your truck is a lot of weight, do not use D rated tires. Higher than D would be even better. It might have been ok with a Four Wheel or ATC camper which weights over a 1000 lb less.
I when I took off the 285 and put 265's back on, I noticed a documented increase of 1.5 to 2 mpg. Reason I had went to larger tires was I thought I'd get a mpg increase, which I didn't see. And this is with a 4.10 ratio also. I don't know why, but that is what I found in real life.
#5
Posted 14 January 2011 - 05:20 AM
Would that be because the odometer needs to be adjusted to accomodate the larger diameter wheel? A larger tire would make the odometer/speedometer appear to be turning more slowly, which would make it appear that you're going fewer miles per gallon. Was this GPS documented or odometer documented? Or am I wrong about this?I when I took off the 285 and put 265's back on, I noticed a documented increase of 1.5 to 2 mpg.
#6
Posted 14 January 2011 - 06:22 AM
Would that be because the odometer needs to be adjusted to accomodate the larger diameter wheel? A larger tire would make the odometer/speedometer appear to be turning more slowly, which would make it appear that you're going fewer miles per gallon. Was this GPS documented or odometer documented? Or am I wrong about this?
You are correct. When comparing mpg of a 285 vs. a 265, you add 7% to the 285 calculation.
From Baja to the Arctic and all places between!
www.generubinaudio.com
Dodge 4x4 2500 Cummins, 6 spd manual, ATC Ocelot Shell. Tesla Model S, 85KWH, 2018 Tesla Model 3 (3 of them!!)
#7
Posted 14 January 2011 - 03:05 PM
Would that be because the odometer needs to be adjusted to accomodate the larger diameter wheel? A larger tire would make the odometer/speedometer appear to be turning more slowly, which would make it appear that you're going fewer miles per gallon. Was this GPS documented or odometer documented? Or am I wrong about this?
When I compared odometer to GPS I found I needed to add 6% to miles traveled with larger tires. Odometer is very close with 265's. Mileage was calculated with corrected miles driven.
#8
Posted 14 January 2011 - 05:12 PM
The difference between D rated and E rated is not necessarily weight carrying capacity but more precisely air pressure capacity. The D's are 65 pounds max, the E's are 85 pounds max.
True and not true - There are D rated tires with the same weight rating as similar E rated tires. But when you go to E rated tires you get another rating up in the sidewall category from "8-ply" to "10-ply". Not that they have 10 sidewall plys anymore (probably 2 or 3) - but it is a stiffer sidewall eitherway.
#9
Posted 15 January 2011 - 09:15 PM
True and not true - There are D rated tires with the same weight rating as similar E rated tires. But when you go to E rated tires you get another rating up in the sidewall category from "8-ply" to "10-ply". Not that they have 10 sidewall plys anymore (probably 2 or 3) - but it is a stiffer sidewall eitherway.
Thanks to all for your thoughts on my questions.
I definitely will go with an "E" rated tire, that extra sidewall firmness and stability is worth it I feel.
About MPG with 285 vs 264 (or stock 245 on my Dodge), I have read that part of the MPG loss with taller/wider tires is due to the wider tire, and I suppose additional friction of them making contact with the road.
I'll probably go with 265/75 configuration in "E" rating of course. Probably a good compromise (keep engine revs down a bit, maintain good MPG).
All the best,
--Robert
#10
Posted 12 April 2013 - 04:29 PM
My question is the tires. I have Hankook Dyna Pro 315/75/R16 tires. With the above stated modifications, are these tires okay? The camper wieghts 1950 Dry. Do I need to buy E rated tires?
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