Community Forums

19481955 · 06-28-2013, 04:57 PM

We have a 2002 Dutchstar DP that has 275/70 22.5 tires on front and rear. The front are almost new but the back Michelins need replacing. I have been reading on other posts that going to a 275/80 tire improves the ride,(it is already great but if the 80's make it better ) Anyway I emailed Newmar and they stated it is best to keep the same tire sizes that are stamped on the ID plate which are the 70's... Would there be a problem you think by changing the rears to an 80 and keeping the 70's in front? Thanks for your input!

ru499 · 06-28-2013, 05:06 PM

The tires have a 2" diameter difference. Thats quite alot, will change your final drive ratio, plus there might not be enough clearance for the larger tire. Stick with OEM size.

Brigadoon · 06-28-2013, 07:20 PM

I changed mine to the 80's years ago. I hated the 70's and will not go back to them. I changed the front first and the rears a couple of months later since I did not like the slightly tail down angle. Spartan Chassis said the was no problem running the smaller diameter on the rear. I don't know if the load on the front tires would increase with the smaller diameter on the front. Moving from the 70's to the 80's resulted in about a 5% drop in rpms at the same mph. For me that resulted in about a 3-4% increase in fuel mileage at my 62 mph cruise speed. And yes they ride better than the 70's. However, you need to check your fender clearences in the front as there may be different wheel well contours from year to year on the DSDP. By the way, I had to go to load range H on the front to make it work.

Mr_D · 06-28-2013, 07:30 PM

We have a 2002 4090 DSDP. I have 305/70's on the front and 275/70's on the rear. I needed the larger tires on the front to carry the weight and there wouldn't have been clearance for the 275/80's as far as I can see, plus they didn't add enough capacity for ours. You might be able to get 275/80's on though.

SarahW · 06-28-2013, 09:59 PM

Quote:

Originally Posted by 19481955

We have a 2002 Dutchstar DP that has 275/70 22.5 tires on front and rear. The front are almost new but the back Michelins need replacing. I have been reading on other posts that going to a 275/80 tire improves the ride,(it is already great but if the 80's make it better ) Anyway I emailed Newmar and they stated it is best to keep the same tire sizes that are stamped on the ID plate which are the 70's... Would there be a problem you think by changing the rears to an 80 and keeping the 70's in front? Thanks for your input!

I think I would stick with what Newmar says is the correct size.

vraines · 06-29-2013, 06:35 AM

How much extra do the 275/80's cost? I suspect that they will cause a clearance problem up front.

vraines · 06-29-2013, 06:38 AM

Sorri, I hit the send button too soon. I realize you are not considering front tire upsizing, but on a Dutch Star that is where the extra capacity is needed. Not sure what you expect to gain?

Gary RVRoamer · 06-29-2013, 02:00 PM

There is no problem using different sizes front & rear - you just may not be able to rotate tires, should that ever become desirable. I'm running 11R22.5's on my rears and 295/80's on the front right now. I switched sizes (which are nearly identical in diameter and revs/mile) because the 11R's are more widely available and much less expensive, but they lack enough load capacity for me to use as front tires.

As to whtehr 275/80 is a good choice for your rear axles, I'll leave that forothers to debate.

19481955 · 06-29-2013, 02:41 PM

Thanks everyone for your input on changing tire sizes. Gary brought up a good point with staying with the same size in case you ever wanted to rotate them so will probably stay with the 70's all around. Thanks again!