halfkoreanboy

So i have a 97 Accord f22b1 automatic and i cant seem to crack 300 miles to a full tank mostly like 275 and the gas light comes on.....I got a/c on full blast almost all the time and 17 inch wheels with 225/45/17 and all city driving no high way and when i take off at a light it feels like the car has 5 ft lb of tq lol like a golf cart could take off quicker. With A/C off acceleration feels a lot better but still i gots to have a/c im a sweater in humidity. So i bought some 92 prelude si wheels today they got 205/60/15 on them almost bald and im going to go ahead and put some new 195/60/15 is there a major difference in mpg loss between the 205 and 195 ? I kinda like the way the 205s look,It show on the calculator the speedo will be off,just curious did anybody notice mpg difference between the 205 vs 195 60 15? If there is a big difference ill just stick with the 195s lol. I figure im getting bad mpg becasue of the heavy 17s with 225/45s on them with the a/c on...I could have swore on my 1999 accord with f23 got close to 350ish to the tank with a/c on all day

holmesnmanny

it's only going to be different in theory because the oem tires are smaller...your actual mgp's will not change at all..just your calculations based on the wheel size difference

holmesnmanny

I'm going to be more specific.

Right now, think of your tires only in terms of wheel circumference. There is more circumference so your odometer is going to show less miles and your speedometer is going to show less mph because it thinks after x amount of time that you're getting y amount of miles and mph even tho it's actually y + z amount because it's actually taking longer for the wheel to turn one revolution.

I actually got a ticket once when i bought an accord with 17 inch wheels. I was going 50 in a 45 in front of a cop and he pulled me over saying i was going 55. I was going to fight it but then came to this conclusion.

chrisnick

Weight makes a big difference, as does how you drive. I get over 400 to a tank pretty easy, but my commute is about 30 miles one way, and I don't drive around much else. I get on it when merging onto the highway, but that's about it. I set it to 70-80mph and let it sit on cruise. My car's a 5-speed though. I get on average about 30+/- mpg a tank. Pay attention to tire weight and pressures, I jumped from about 28mpg to over 30 just by putting my air pressure to the max recommended on the sidewall(I think they're at 45, haven't checked them in a couple weeks). 185/65/15. A taller tire will only help you attain better gas mileage only if the rolling resistance and weight is not more than the tire previously on there. Sounds like you do a lot of city driving, and that plus the A/C constantly on nukes your mileage. My A/C needs a recharge, but it isn't humid enough here for me to complain yet. I'll probably be crying next month if I don't get it fixed though.

Also, make sure you air intake filter is clean, and your spark plugs are properly gapped and not trashed. Tire pressure, plugs, and air filters make a HUGE difference.

Personally, I like to try to keep wheel/tire combo around 35lbs total weight or less, which is pretty hard while trying to maintain the same diameter tire. Tirerack.com has been AWESOME for this research, they list tons of tire stats and you can compare side by side. Pretty much the cheapest prices, too.

Shmallow

there are many factors at play here- a lot of variables that can have an effect on mpg. A wider tire, all other variables controlled (wheel size, wheel weight, tire type, other tire measurements...) will in theory have more rolling resistance therefore decreased mpg. with the small change you're talking about, you may not see a significant difference.

in my experience the type of tire has a greater impact on mileage. i've seen the best mileage with a T-rated, high-mileage (80-90k) plane jane tire. a better handling H-rated, "summer performance" tire had about a 2-3% impact on milage. and this was on a lighter wheel. I recently changed out a set of 185/60-14 on steel for a 195/55-15 on aluminum. wheel & tire combo weights were identical to the 10th of a pound. the new tires were a higher quality brand and claim low rolling resistance despite being a "sporty" tire. so far i've yet to see a change in milage. so the wider tire on a bigger wheel but with the same weight and similar OD (a few fractions of an inch larger) hasn't changed the milage likely because it was designed to have low rolling resistance.

halfkoreanboy

Thanks for the replies.....Today i did notice better acceleration with the a/c on with the 15s vs the 17s...Im going to buy some new 195/60s soon and calculate and see what happens......I think ill stick to what the book says on tire pressure 32 psi.....Ive noticed on other cars when i put more air it did run more efficient but tires wore out real quick and i slid more in the rain lol and i noticed when it rained i hydroplaned a lot on freeways felt very unsafe.

Schister66

Larger diameter rims/tires change your gearing and acceleration rate. Since the engine will have to work harder to accelerate, it will use more fuel. Having said it, there generally isn't much of a size difference between most rim/tire combinations. The 17s on your car could be costing you some gas mileage. Further, narrower tires have less rolling resistance and should therefore aide in increasing your mileage.

Things you can do:
-o2 sensor
-new plugs/wires
-check tire pressure (dont add too much air...better mileage comes at the tradeoff of a smaller contact patch with the road. As you mentioned, this can cause darty handling and loss of traction, especially in rain/snow)
-limit AC use

halfkoreanboy

Cool cool thanks....yea i remember having my tire pressure up above 40psi with stiff suspension taking a curve at 40 onto a on ramp in the rain and i was going backwards and took out a a whole section of gurad rail and totaled my Integra,now with stock psi it feels much much safer in the rain. I personally would never recommend anything but stock psi for tires no matter the size 15s 16s or 17s i believe i read that stock psi even on low pros is safest way to go.....

Its funny i bought my 92 prelude si wheels and they had like 50 psi of air in all of them and they came off a si with front end total ?????? I imagine he did some hydroplane into something but jut a guess lol


Well drove the car alot today and its official with a/c on full acceleration is sweet now.....I can keep up with traffic and with a/c off even better lol.....now i will see if i can crack 300 miles per tank at least with a/c on still deciding to get new 205/60/15 or 195/60/15 the 205s look like too much sidewall.....so i may just stick with stock size and see how it goes with the 195s might look better in my eyes also.....certain angles 205s look nice but at different angles they look like fat tires lol

halfkoreanboy

Well i decided on the 205/60/15 size since the v6 came with it anyway it could not hurt much LOL. I thought it might look better with the drop. Im very happy with acceleration when the a/c is on and when its off it feels like a new car lol Im sure 195 would have been better but it seemed to small on the side wall height and my lip would have touched the ground. And i love the look with the SI wheels they have no bends and barely any curb rash i got lucky. I bought 2 brand new tires up front and next week ill get new rear tires when i get paid.

halfkoreanboy

Here are a few pics i need to bring the size down on my Camera lol