furiousjohnson

Have just purchased an '89 Wagovan FWD 5spd w/factory 13" wheels and only 48k original miles. Want to increase rim and tire size. How big can I safely go? Car revs at over 3000rpm at highway speed, so would like to lower this and improve comfort somewhat. Any thoughts?

PooN_Lude

15's or 16's will be ideal. I have 16x7's on my wagon, can't complain

furiousjohnson

Thanks. What tire size before it gets too big for the wheel well. Tire shops will only recommend factory specs for liability reasons.

senor honda

The way some people determine tire/rim diameter is to measure
around the outside of the stock tire......then measure around the outside of the tires you are considering putting on....A general rule is that as you go up in rim size 13-14-15-etc., you go down in profile number 70-60-50-40-etc.

By keeping the outside-of-the-tire measurement the same,
it keeps your speedo accurate, and avoids tickets.

If you decrease RPM's on the highway by changing tire diameter,
you will have a speedo that is reading in your dis-favor, and the cop
may not be sympathetic.-Bob

furiousjohnson

Thanks for the hint. I was hoping to be able to rev. down the engine a bit and hopefully up the fuel economy at the same time. It has plenty of pep and doesn't seem necessary to run it at 3500rpm on flat highways. If I still wanted to try a larger tire (circumference), couldn't I just diminish my speed by the same percentage as an overall % increase in tire circumference?

PooN_Lude

3,500 is still a pretty low rpm for highway speeds. What kind of gas mileage are you getting?

FrodoGT

the d series makes best mileage at 2900-3200 rpm.

That said. 15x8 +36 offset is the widest wheel you will fit in there, and as for tires you could fit a 245/45/15 in the front but in the rear you'll only manage a 205 without major work. Keep in mind to fit these you'll need serious fender rolling on all corners. These are just absolute max sizes.

furiousjohnson

Between 30-33 on the highway. I expected it to be somewhere around 36-38. It's still a lot better than my Saab wagon or my Ford F150 though, so I'm not going to complain that much. I may just replace with factory OEM, but since the tires are ready to be replaced I figured this was the time to sort through all these issues.

furiousjohnson

My main goal is increasing fuel economy and diminishing engine wear. I really like the off-the-shelf look of the wagovan and don't want to muck with it too much. Though I suspect a wider stance on the tire would give a more comfortable ride.

jlude90

the larger the wheel the more weight you're turning, the wider the tire the more rolling resistance you'll have. you'll also accelerate quicker with the smaller wheels/tires