Do wider tires = larger void ratio? 285 vs 275?

[Steve1199]

So, this may be a dumb question but i'm in the search/review/research phase leading up to an upcoming tire purchase.

 

My question for now is, do wider tires have a higher % void/block ratio than narrower tires? Basically, when looking at a 285 vs 275 tire, will they both have the same tread block size, whit the 275 just having slightly less spacing between the blocks or are the blocks on the 275 actaully smaller than the 285 so the void spacing is the same(ish)?

 

for reference, i'm looking at tires between these sizes:

 

275/70/18 i "think" this will fit without a lift/level from reading, but think it will be really tight, not sure on full wheel travel without rubbing if i'm off road. hesitant on this size as i'm not wanting to do a lift/level at this moment.

 

these two are nearly the same height

275/65/18 - these should fit easily i'm guessing

285/60/18 - these should fit easily i'm guessing

 

i drove 30K miles a year on the road, but like taking a few trips off road, mostly trails, sandy areas, not really to much mud or rocks, see some snow on trips up north each year. i'm not doing anything serious off road (its my daily driver).

 

the top two tires i'm looking at now:

BFG AT KO2 - most practical for an all around AT tire and likely all i'll ever really need preformance wise for what i do off road (plus the snow traction is important as i travel up north (TN and Northern Michigan) every year

Cooper ST MAXX - like the look, aggressive tread, big voids. probably not the most practical if i'm honest about my Needs vs Wants

GY Duratrac - like the looks and the off road/on road/winter capabilities, but worried about their noise on the road and have read mixed reviews on them noise wise (8 hour road trips once or twice a month and 1 hour drive each way to work every day)

 

my concern with the 285 is both cost (more expensive) and being wider i'll take a larger hit in fuel mileage due to wider tire.

 

i'm not sure i want to go wider than 285 as i'm keeping stock wheels and i think to wide will hurt mileage and hurt winter roads traction

[Sooperdave]

Lets see... More void between contact blocks will produce more noise. I don't think this alone will effect anything else. Height and weight of tires is the major factors in having consequences. Weight effects fuel mileage and some performance(braking/accelerating). Typically AT tires are going to be fairly heavy vs a standard highway tire. Now throw in additional height to the equation and the overall gear ratio suffers which can effect fuel again as well as performance. If all things are equal to factory weight and height, then nothing should suffer even if you go to a bit wider tire. I switched from a 245/40/19 to a 275/35/19 on my G8 as well as I changed wheels. I shopped for the widest contact patch in a 275(yes this varies) as well as the lightest tire. I ended up with a Continental DW that didn't break the bank but wasn't cheap either. In the end weight and height was identical to factory and had no ill effects with the wider tire. You have to ask yourself what do you want? That's quite a few miles per year you are driving and will add extra expense if your not careful. If you keep the weight fairly close and height the same as stock then you really shouldn't see much change if any effect either way. If you do go extra weight and height, then you will pay to play. Hope that helps. Good luck!

[Steve1199]

yep, definitely not expecting a "free lunch" in terms of mileage with taller/wider tires. just trying to decide/find out if theres a major difference between 275 vs 285 vs say 295 in terms of mileage and resistance. i also know the wider the tire, the more stress it puts on the suspension joints (weight further out from center of wheel) and don't want to go that much wider if it will increase wear of other suspension parts notably quicker.

[Steve1199]

and for reference, my stock SR-A tires are 265/65/18 and only weight approx 36lbs. most of these AT tires i'm looking at are in the 55-58lb range, so, i know in town driving will take a hit due to weight. i assume highway driving won't take as much of a hit in mileage.

[Sooperdave]

One thing to keep in mind is how much tire width will the wheel allow you to add. When you go past the range its designed to handle it starts to look odd for one but it will effect handling. I don't think you should worry about the suspension with a bit wider tire. This comes in to play when you change the offset of the wheel and it kicks it outward. This is when stress is added.

[Sooperdave]

Also check into the Hankook DynaPro tires. They seem to be lighter compared to other AT tires.

[Steve1199]

i think the stock rims are 8.5 inches, right?

[silveradonationfan15]

I wanted to run 275/70/18's KO2's and I couldn't because they will void the warranty on the fount end if they caused any issues, and plus they barely fit, They would rub. I'm running 265/70/18 and that's the biggest diameter I could go, The GM dealers told me you has to stay with in a 3% diameter difference to keep everything good. I managed to get them to let me go to a 3.4% difference. Lets just say, if you installs that particular tire you will lose many mpg's I went from 19.5 to a 11.0 ( mostly highway) at some points I gets lower. .... I couldn't believe how much difference. it gave my truck another inch or more clearance, I bought mine mostly for a winter tire and I had intensions to leave it on as a all season, but now I think that will change.

[Steve1199]

I wanted to run 275/70/18's KO2's and I couldn't because they will void the warranty on the fount end if they caused any issues, and plus they barely fit, They would rub. I'm running 265/70/18 and that's the biggest diameter I could go, The GM dealers told me you has to stay with in a 3% diameter difference to keep everything good. I managed to get them to let me go to a 3.4% difference. Lets just say, if you installs that particular tire you will lose many mpg's I went from 19.5 to a 11.0 ( mostly highway) at some points I gets lower. .... I couldn't believe how much difference. it gave my truck another inch or more clearance, I bought mine mostly for a winter tire and I had intensions to leave it on as a all season, but now I think that will change.

you went from 19.5 to 11? that seems like a huge drop. i'd expect 1-2mpg drop average (maybe slightly more) for only an inch taller tire (31.6 vs 32.6). what tire did you go with?

 

i've got a 28,500 mile average of 18.5mpg, with about that in my around town driving and about 20-21 on the highway depending on how fast i drive

[silveradonationfan15]

you went from 19.5 to 11? that seems like a huge drop. i'd expect 1-2mpg drop average (maybe slightly more) for only an inch taller tire (31.6 vs 32.6). what tire did you go with?

 

i've got a 28,500 mile average of 18.5mpg, with about that in my around town driving and about 20-21 on the highway depending on how fast i drive

I know, I only went from a stock oem goodyear sr-a 265/65/18 to a bf Goodrich ko2 265/70/18... when I getting my average numbers, I only goes between 45-60mph, Actually I barely sees V4 on my screen anymore, also I went a 90 mile trip last week and I burned almost a 1/2 a tank of gas, It was mixed driving.

[silveradonationfan15]

 

[Steve1199]

I'm also hesitant for the 33" tire as i do still plan to and need to tow with this truck and don't want to hurt the towing capacity to much with a much larger tire.